After trial commences, amendments require proof that due diligence could not have raised them earlier.

The petitioner, as plaintiff, brought a commercial suit seeking possession of leased premises, arrears and other reliefs.

The respondents filed a written statement and counterclaim on 31 October 2023, pleading that the petitioner had failed to secure conversion of the property from industrial to commercial use and that they had suffered financial loss.

When the suit had reached the stage of recording the plaintiff’s evidence, the respondents sought to amend the counterclaim to add a prayer for damages, relying in part on information obtained under the RTI Act about a conversion application filed in April 2024.

The Commercial Court allowed the amendment; the petitioner challenged that order under Article 227 of the Constitution.

Order VI Rule 17 CPC permits amendment of pleadings where necessary to determine the real questions in controversy, but its proviso bars an amendment after commencement of trial unless the court is satisfied that, despite due diligence, the party could not have raised the matter earlier.

As explained in Vidyabai v. Padmalatha and Basavaraj v. Indira, satisfying this requirement is a precondition to allowing a post-trial-commencement amendment; the applicant bears the burden of establishing due diligence.

A liberal approach to amendments, including the principles discussed in Revajeetu Builders and LIC v. Sanjeev Builders, does not displace that statutory condition.

The Court also considered the Commercial Courts Act, 2015’s objective of expeditious adjudication of commercial disputes.

The Court found that the respondents had already pleaded the petitioner’s failure to convert the property, its alleged unsuitability for the intended purpose, and the resulting financial loss.

The later RTI information and supporting documents did not establish that the underlying facts or the claim for consequential damages could not have been raised when the counterclaim was filed.

The amendment application and supporting affidavit did not plead or demonstrate the required due diligence.

The Commercial Court therefore erred by allowing the amendment without addressing this mandatory condition; permitting it at that stage would also risk further delay in the commercial suit.

It allowed the writ petition, set aside the order dated 10 June 2025, and dismissed I.A. No. 20 seeking amendment of the counterclaim.