Other banks will also be hit by HM Revenue & Customs' crackdown on offshore accounts, after a landmark ruling by the special commission forced Barclays to hand over the details of thousands of customer accounts.

A Barclays spokeswoman confirmed that the ruling by special commissioner John Avery Jones did refer to Barclays specifically, but added that the ruling would not be limited to the FTSE100 bank.

'This issue is not specific to Barclays. It is an industry issue that will affect other financial institutions,' she said, adding that Barclays will comply with the ruling.

HMRC hopes that the ruling will enable it to yield £1.5bn in unpaid tax. Government officials will now be able to search individual records and fish out people who have not declared income on cash held in offshore centres such as the Channel Islands.