Ranjit Singh Sarkaria, J. - This revision-petition is directed against an order, dated 30th August, 1968, of the learned Subordinate Judge, First Class, Jagadhari, by which he dismissed the plaintiff's application for amendment of the plaint. It arises out of the following facts. 2. The plaintiff-firm, Messrs The Punjab Rajasthan Timber Trading Company, Yamunanagar, instituted a suit for the recovery of Rs. 29,209.88 (including Rs. 18,046.98 as principal and Rs. 11,162.90 as interest), alleging that the plaintiff-firm has been supplying timber and packing cases for the period 25th November, 1960 to 21st November, 1963, to the defendant (The Wearwell Co. (India) Ltd., New Delhi) with effect from 25th November, 1960. There was thus a single continuous transaction. A current account was opened and whatever supplies were made by the plaintiff were debited to the account of the defendant and whatever payments were made by the defendants were credited to the same account. A sum of Rs. 18,046.98 fell due from the defendant, which amount is claimed with interest at the rate of 12 per cent per annum. It was further pleaded that the defendant had made part-payments by cheque on 27th May, 1963 and 16th December, 1963 in the said account. The suit, therefore, instituted on 25th May, 1966 was within limitation, counted from the date of the aforesaid part-payment. The plaint was signed by Balmukand, one of the partners of the plaintiff firm. The parties closed their evidence. During the course of final arguments, the defence counsel raised an objection that the original firm, which was carrying on the business of timber and packing cases under this very name, had come into existence on 27th June, 1960 and was dissolved on 31st March, 1963, and the plaintiff-firm, which came into being on 1st April, 1963, bearing the same firm name, was a different firm and it could not claim the amount, if any, due to the dissolved firm. Thereupon, the plaintiff made an application on 2nd August, 1968, seeking permission to amend the plaint and to add this plea :- "That the plaintiff-firm was initially constituted on 27th June, 1960 and consisted of five partners, namely, Balmukand, Muni Lal, Jiwan Ram, Kanta Devi and Pritam Kumar. It started and carried on its dealing with the defendants as hereinafter mentioned. Subsequently, Jiwan Ram, one of the partners, retired on 31st March, 1963, and the firm was dissolved and all the business, assets and liabilities of the said firm were taken over by the remaining four partners who constituted themselves into a partnership with effect from 1st April, 1963, and continued their dealings with the defendants, keeping intact their rights and liabilities as they existed before the dissolution of the previous partnership on 31st March, 1963.... The plaintiffs were thus entitled to recover from the defendants all the dues arising out of the transactions of purchases which the defendants made with the firm as it existed from 1960 till 31st March, 1963 as also with the firm as it was constituted on 1st April, 1963." 3. A preliminary objection has been raised by Shri D.D. Sharma, learned counsel for the defendant-respondent, that this revision is not competent because even a wrong exercise of its discretion under Order 6, Rule 17, Civil Procedure Code, or an erroneous construction of those provisions by the Subordinate Court, which undoubtedly had the inherent jurisdiction to try the case, would not amount to "the exercise of its jurisdiction illegally or with material irregularity" within the meaning of Section 115, Civil Procedure Code. In support of this contention, reliance has been placed on Ratilal Balabhai Nazar v. Ranchhodbhai Shankarbhai Patel and another, AIR 1966 SC 439 and L'Union Fire Accident and General Insurance Co. Ltd. v. Shri O.P. Kapur and others, AIR 1963 Punjab 397. 4. In reply Mr. H.L. Sarin has urged that so far as this Court is concerned, it has consistently taken the view that if in refusing the amendment of the pleading the Subordinate Court exercises its discretion in a manner contrary to well-settled judicial principles, it "fails to exercise a jurisdiction vested in it by law" within the meaning of clause (b) of Section 115 of the Civil Procedure Code. Reference has deemed made in this behalf to Shri Har Sarup Gupta v. Shri S. Aggarwal and others, 1960 PLR 694; Khachera and others v. Khimman, Civil Revision 398 of 1969, decided on 7th August, 1969 and Rama Shankar Tiwari v. Mahadeo, 1968 ALJ 109 (Full Bench). Mr. Sarin has also pointed out that Ratilal Balabhai Nazir's case, does not advance the contentions of Shri Sharma because the precise question before this Court was not considered in that case. 5. It appears to me that the preliminary objection raised by Shri Sharma is not sustainable. 6. There was at one time a conflict of opinion among the various High Courts in India as to whether an interlocutory application is a `case' and an interlocutory order passed thereon is a `case decided' within the meaning of Section 115, Civil Procedure Code. This conflict was set at rest in S.S. Khanna v. F.J. Dhillon, AIR 1964 SC 497, and it is now concluded that the word `case' in Section 115, Civil Procedure Code, includes interlocutory orders passed in a suit. That is to say, an order disallowing an amendment under Order 6, Rule 17, Civil Procedure Code, is `a case decided' within the meaning of Section 115. 7. It is true that under Order 6, Rule 17, as is indicated by the word `may', the Subordinate Court had a discretion to refuse or allow the amendment and the High Court does not interfere in revision with discretionary orders unless the trial Court exercises that discretion so unjudicially and capriciously and contrary to well settled legal principles on the subject, that the matter falls within the purview of any one or more of he clauses (a), (b) and (c) of Section 115, Civil Procedure Code. The test to be applied is : Does the error committed by the Subordinate Court in refusing the amendment amount to erroneous assumption of jurisdiction, or erroneous failure to exercise jurisdiction or the exercise of jurisdiction illegally or with a material irregularity ? In short, the error must be so palpable and of such magnitude that it strikes at the very root of the jurisdiction of the Court to pass the particular order it did. Well then, what is meant by `jurisdiction' in Section 115 ? The word `jurisdiction' in this section has been used in its broad legal sense. The expression is not confined to the jurisdiction to entertain the suit or appeal. The Court may have jurisdiction to entertain the suit, yet it may have no jurisdiction to pass the particular order in question. If it does so by improperly clutching, assuming or exceeding its jurisdiction, the case is one under clause (a) of the section. If the Court having jurisdiction to deal with a certain matter in a certain way, acting clearly contrary to principles declared as law by the Supreme Court, declines jurisdiction, the case falls under clause (b) of the section. 8. In Pandurang Dhondi Chougule and others v. Maruti Hari Jadhav and others, AIR 1966 SC 153, Gajendragadkar, C.J., after referred to two other judgments of the Supreme Court, observed :- ".... a distinction must be drawn between the errors committed by Subordinate Courts in deciding question of law which have relation to, or are concerned with, question of jurisdiction of the said Court, and error of law which have no such relation of connection. It is, we think, undesirable and inexpedient to lay down any general rule in regard to this position with precision or to deal with it exhaustively may create unnecessary difficulties. It is clear that in actual practice, it would not be difficult to distinguish between cases where errors of law affect, or have relation to, the jurisdiction of the Court concerned, and where they do not have such a relation." 9. The rule in Pandurang's case, was reiterated by the Supreme Court in Ratilal Balabhai Nazar's case ibid, and it was held that an erroneous construction placed on a statute by the trial Court does not amount to exercising jurisdiction illegally or with material irregularity and would not furnish a ground for interference under Section 115, Civil Procedure Code. Ratilal Balabhai Nazar's case and Pandurang's case are quite distinguishable from the facts of the present case. In Ratilal Balabhai Nazar's case, the lower Court had placed an erroneous construction on Section 12 of the Bombay Rents, Hotel and Lodging House Rates Control Act, 1947. In the present case, there is no question of any provision of the statute being misconstrued. The main question is, whether in the circumstances of the case the Subordinate Court unjdicially and illegally refused to exercise jurisdiction vested in it. I have quoted above the observations of their Lordships of the Supreme Court from Pandurang's case to show that it is neither possible nor expedient to lay down any general rule for distinguishing an error committed by a Subordinate Court in deciding questions of law which have relation to or are concerned with questions of jurisdiction of that Court and errors of law which have no such relation or connection. If the error goes to the root of the matter and is of such magnitude that it irresistibly leads to the conclusion that the refusal of the said Court to allow the amendment amounts to erroneous failure to exercise jurisdiction vested in it, the High Court would interfere in revision. 10. In circumstances similar to the present case, Grover, J. in Har Sarup Gupta's case, ibid, held that where he amendment which is sought is necessary for the purpose of determining the real question is controversy and the trial Court by applying wrong principles declines to allow amendment of the written statement, it fails to exercise jurisdiction which vested in it and the High Court will interfere in revision and allow the amendment. Same view was taken in Khachera's case ibid, by Harbans Singh Acting C.J. I am in respectful agreement with that view. The authority of those decisions has not, in my opinion, been adversely affected by the law enunciated by the Supreme Court in the aforesaid cases. I would, therefore, overrule the preliminary objection of Mr. Sharma. 11. On merits, Mr. Sarin contends that the amendment sought was necessary to determine the real question in controversy between the parties, and in refusing that amendment the Court below had "failed to exercise jurisdiction vested in it" within the meaning of clause (b) of Section 115, Civil Procedure Code, and, as such, this Court should interfere in revision and set matters right by allowing the amendment. Stress has been laid on the fact that even if the amendment is allowed, the parties will remain the same and the cause of action, i.e. the grounds of claim and the amount claimed, will also remain the same. The only thing which is sought to be clarified by means of this amendment is, that the business of the dissolved firm has been continued by the new firm under the old name and style, and all the partners remained the same excepting one who retired. It was expressly provided in the partnership deed that the assets, debts and liabilities of the old firm had been taken over by the new firm. Mr. Sarin has also pointed out that this objection about the competency of the plaintiff firm to recover debts due to the old firm, was never raised in the written statement by the defendant. The objection was taken for the first time at the time of final arguments, and that according to the well established rule of pleading, the trial Court should not have permitted the raising of this objection which had no foundation in the pleadings, and, if it did grant the permission to raise that objection, it was but proper for it to allow the plaintiffs to amend the plaint to enable them to meet this objection which had taken them by surprise. In support of these contentions, reference has been made to A.K. Gupta and sons v. Damodar Valley Corporation, AIR 1967 SC 96; Jai Jai Ram Manohar Lal v. National Building Material Supply, AIR 1969 N.S.C. 8; L.J. Leach and Co. Ltd. and another v. Jardine Skinner and Co., AIR 1957 SC 357 and Pirgonda Hongonda Patil v. Kalgonda shidgonda Patil and others, AIR 1957 SC 363. 12. On the other hand, Mr. Sharma has contended that the application for amendment was not bona fide made; it was mala fide inasmuch as it had been made after an undue delay. It is stressed that Balmukand, a partner of the plaintiff-firm, was cross-examined on 15th April, 1967 with regard to the dissolution of the original firm and the creation of the new firm. It is maintained that this cross-examination should have put the plaintiffs on their guard to apply for amendment forthwith, but they slept over the matter for more than one year till they made the application on 2nd August, 1968. Another argument is that at the date of the application for amendment, the plaintiff's claim would be time-barred and if the amendment were allowed, it would take away a valuable right which had accrued to the defendant by lapse of time. It is further canvassed that the amendment would be meaningless because the part-payment of 27th May, 1963 could not give the plaintiff-firm a start of limitation either as an `acknowledgement' under Section 18 or as a `part-payment' under Section 19 of the Limitation Act, 1963, for the simple reason that it had not been made in favour of the original creditor. 13. I have carefully considered the contentions canvassed on both sides. There is a good deal of force in what has been said on behalf of the revision-petitioner. It is true that Balmukand, P.W. 3, cases was cross-examined with regard to the constitution and dissolution of the old firm and re-constitution of the plaintiff-firm, several months before the objection was actually raised by the defence counsel at the time of final arguments. This circumstance, by itself, was not sufficient to inform the plaintiff that this particular objection would be raised by the defendant and entertained by the Court in spite of the fact that it was not adumbrated in the written statement. The objection was raised on 1st August, 1968 at the time of final arguments. The application for amendment was promptly made on 2nd august, 1968. It cannot therefore, be said that the plaintiff-applicant was guilty of any laches in seeking the amendment. Even if this amendment is allowed, the parties to the controversy and the cause of action will remain the same. The only difference will be that the plaintiff can say and prove how he is entitled to recover the amount due to the dissolved firm. A perusal of the written statement would show that the defendants admitted that they had dealings with the plaintiff-firm and had further admitted that some bills were submitted by the plaintiff firm in respect of the `cases' supplied to the defendant. 14. The amendment is certainly necessary to meet the technical objection raised by the defendant at a very late stage. The amendment will not change the nature of the suit. No less an authority than their Lordships of the Supreme Court have laid down in A.K. Gupta's case, that where the amendment does not constitute the addition of a new cause of action or raise a different case, but amounts merely to different or additional approach to the same facts, the amendment is to be allowed even after expiry of the statutory period of limitation. To the same effect is the rule laid down in L.J. leach and Co.'s case and Pirgonda Hongonda Patil's case and Charan Das v. Amir Khan, AIR 1921 PC 50. The ratio of the aforesaid cases fully applies to the facts of the present case. I have, therefore, no hesitation in holding that in disallowing the application for amendment the trial Court has erroneously `refused to exercise jurisdiction vested in it' within the contemplation of clause (b) of Section 115, Civil Procedure Code. I, therefore, accept this revision-petition and allow the application for amendment. Costs shall abide the result in the trial Court. 15. Let the records of the case be returned forthwith to that Court. The parties are directed (through their counsel) to appear in the aforesaid Court on 6th October, 1969. Petition allowed.