The Office of Fair Trading lodged papers with the High Court after eight high street banks - Abbey National, Barclays, Clydesdale, the HBOS group, which includes Halifax, HSBC, Lloyds TSB, the Royal Bank of Scotland Group, which includes NatWest, and Nationwide Building Society. - agreed to a test case to settle the issue.

The OFT, which has been investigating the charges since March, said it believed they were unfair, but this has been disputed by the banks.

Tens of thousands of consumers have complained about the charges, which are levied on people who breach their authorised overdraft limit, with many taking their bank to court.

Customers can be fined as much as £39 for a single bounced payment. While it has never been revealed how much an unauthorised overdraft actually costs banks, some commentators have estimated it could be as little as £2.