RBS chief Ross McEwan has been told to ‘get his act together’ by the boss of the UK financial watchdog over the processing of compensation claims by small firms it drove to bankruptcy.

The part-taxpayer owned bank has set aside £400 million to cover the bill arising from the activities of its controversial Global Restructuring Group during the 2008 banking crisis.

Andrew Bailey, Chief Executive of the Financial Conduct Authority, made the ‘get his act together’ comments to the House of Commons Treasury Select Committee.

Mr Bailey told MPs it was “unfortunate” the Edinburgh-based bank has disagreed with findings from its report over the bank’s treatment of small businesses.

He said the bank should have accepted its findings, and blamed those disputes for delaying the release date of the interim report.

“I think the report is strongly critical of RBS and I think it is, frankly, unfortunate that RBS have not in a sense accepted that, I think, more readily,” Mr Bailey added.

“I think they should do, because a lot of ... time and a lot of effort and a lot of work has been done on this.”

In a letter to the MPs, Mr McEwan said ‘we deeply regret the mistakes we have made in the past’ regarding some of the division’s customers.

He added: “We fully accept that we did not, in all cases, fully comply with our own policies or always meet the standards of service that we set ourselves.”

He said they “clearly acknowledge” that the bank could have “done better” for business customers.