A High Court judge has refused a party permission to make significant amendments to their claim on the eve of the case coming to trial.

With a hearing due to begin on 10 May, the claimants in Donovan & Anor v Grainmarket Asset Management LLP, sought to make major changes to their case six weeks before. The application was partly opposed by the defendant who said there was insufficient time to prepare a full response to the amended claim.

Junior counsel for claimants, Dominic Howells, told the High Court the late amendment application was because his predecessor was not available for the trial date, and he had brought ‘fresh eyes’ to the case which prompted a change in approach.

Martin Griffiths QC, sitting as deputy High Court judge, said there was no dispute that the application was late. So far as the explanation was concerned, he added, it was ‘not a very good one’.

Case law stated, the judge noted, that a fresh examination of possible arguments by fresh counsel was ‘precisely the sort of reason that does not find favour with the courts’. The judge added that the instruction of new counsel was not in itself a good explanation for a late amendment.

The application itself turned the claimants’ case from a claim for payments due under an alleged contract to a claim that the disputing parties were partners and should be paid accordingly.

The judge noted that a letter to the defendant at the end of March ‘somewhat mischaracterised’ the amendments purporting they were to make ‘minor factual and legal clarifications’. This was unfortunate, said the judge, as the defendant did not appreciate there was any urgency in engaging with the letter.

The defendant said they would suffer prejudice if they had to prepare a fresh defence and counter-claim within the limited timescale. The judge said the re-characterisation of the agreement represented a ‘substantially different case analysis’ which amounted to a burden on and disadvantage to the defendant which amounted to substantial prejudice.