Stewarts Law will file a letter before action to Tesco this week, pushing ahead with plans launched early last year to bring a multimillion-pound claim against the retailer.

The litigation boutique is bringing the action against Tesco over losses suffered as a result of the supermarket group’s £263m profits restatement last October, which wiped more than £2bn from the company’s share price.

The firm extended its deadline for applications from shareholders to join the claim in April, revealing it had amassed more than £200m in claims.

Stewarts’ lead partner on the case Sean Upson said the number of shareholders involved had now passed the desired total and the firm was working on establishing a claimant committee and launching the first stages of the claim with funders Bentham Europe. Tesco will have around 15 days to acknowledge receipt.

The supermarket chain has turned to Freshfields Bruckhaus Deringer to defend the claims and advise on an ongoing investigation by the Serious Fraud Office into its “accounting errors”. Freshfields has drafted in a team from Kingsley Napley to work on the criminal law aspects of the probe.

Stewarts Law was just one firm of a handful understood to be preparing claims against Tesco, which suffered a number of executive redundancies after the scandal.

Scott & Scott, McGuireWoods and RPC were all expected to launch claims though the issue has stagnated pending the result of the SFO investigation.

Stewarts will be the first to launch a claim with Upson stating the uncertainty over the result of the probe and rumours it could reach a deferred prosecution agreement (DPA) with the fraud office meant claimants were keen to push on with the action.

Upson has instructed One Essex Court’s Stephen Auld QC for the litigation. Stewarts is working with commercial litigation capital funders Bentham on the case.