JJB Sports was fined over shirt pricing in 2003

Under powers granted it in the Enterprise Act, Which? has the right to launch a case of this kind at the Competition Appeals Tribunal.

Which? wants people who bought shirts from JJB in 2000 and 2001 to contact them as part of the case.

JJB told the BBC it was considering a response to the Which? action.

The company added: "JJB Sports notes the Which? announcement that it intends to take legal action against JJB Sports for the sale of replica football shirts during the alleged price fixing of 2000-2001."

Fixing fine

In 2003, JJB was fined �6.7m by the Office of Fair Trading (OFT) over price-fixing.

The OFT's price-fixing case against JJB and nine other businesses followed one of the biggest investigations of its type in the UK.

Ten firms fixed prices for top-selling short-sleeved adult and junior shirts of the England team and Manchester United, the OFT said.

The price of some England football shirts was fixed, the OFT said

At the time, JJB vehemently denied any wrongdoing.

Which? said it wanted to force JJB to compensate consumers by taking a case to the tribunal.

"We hope it will soon be payback time for JJB Sports," said Which? spokesman Malcolm Coles.

"They ripped off their customers, so we think it's only fair they should have to pay them back."

Tribunal

JJB Sports has two weeks to respond. After this time, Which? will consider filing the action at the Competition Appeals Tribunal.

The Tribunal can, in theory, order JJB to reimburse consumers.

Which? first advertised last December for potential claimants to come forward to sue for price fixing.