Chelsea Williams v Daniel Wilkinson

Permission to amend a pleading is discretionary and must be determined under the overriding objective. A very late amendment which threatens a fixed trial date places a heavy burden on the applicant. The applicant must show a strong and sufficiently formulated new case, a good explanation for the delay, and why permitting the amendment serves justice to the parties and other court users. The risk of losing the trial date may itself weigh heavily against permission. The court must balance the applicant’s potential injustice against prejudice, wasted work, delay, court resources and the public interest in proportionate litigation. Serious injury and a high-value claim do not displace those principles. An amendment with uncertain prospects, unresolved factual and expert issues, and no good explanation for lateness may properly be refused.

The claimant brought a clinical negligence claim against an osteopath concerning an admitted failure to advise her to attend hospital urgently when she exhibited symptoms of cauda equina syndrome. Causation was disputed, including whether earlier referral would have resulted in materially earlier surgery and whether any earlier surgery would have improved the outcome.

The claim was listed for a seven-day trial commencing on 15 June 2026. The claimant applied shortly before trial for permission to amend her pleaded causation case, to rely on further factual evidence, and to adduce additional expert evidence. The proposed amendment introduced alternative pathways involving a return home, contact with NHS 111 or 999, ambulance transfer, and surgery during the night or early the following morning. If allowed, the trial date would be lost.

1. Application refused. Permission to amend the Particulars of Claim and the consequential applications for additional factual and expert evidence were refused.
2. Under Civil Procedure Rules 17.2 and 17.3, amendment is a matter for the court’s discretion. The overriding objective requires a balance between the injustice to the applicant if permission is refused and the injustice to the opposing party, other litigants and the administration of justice if it is granted.
3. The principles summarised in Quah Su-Ling v Goldman Sachs International [2015] EWHC 759, and approved in Nesbit Law Group v Acasta European Insurance Company Limited [2018] EWCA Civ 268, applied. A very late amendment is one made after a trial date has been fixed where permission would cause that date to be lost. In that situation the applicant bears a heavy burden to demonstrate the strength of the new case, a good explanation for delay, and why justice requires the amendment.
4. The proposed amendment was not shown to be bound to fail, but its prospects were uncertain. It failed to address when the claimant would have contacted NHS 111 or 999, the likely ambulance delay, MRI timing, the 05.45 decision that surgery could await the morning, and the subsequent prioritisation of surgery. Further factual investigation, expert reconsideration and possibly further expert evidence would have been required.
5. The causation issue had always been the claimant’s responsibility. The defendant’s report had put the counterfactual timeline in issue, and the claimant had not provided a good explanation for failing to investigate and plead the revised case earlier. The defendant was entitled to respond to the case actually pleaded and was not required to investigate an unpleaded alternative.
6. Loss of the fixed trial date, substantial delay, duplication of work, difficulty investigating events years later, and disproportionate use of court resources weighed heavily against permission. The value of the claim, the admitted breach and the potential injustice to the claimant did not outweigh those factors.
7. Cobbold v Greenwich London Borough Council (unreported CA, 9 August 1999) did not justify allowing the amendment. The general preference for determining the real dispute must be qualified in a very late application by the need to protect trial fixtures, other litigants and proportionate justice.