Gordon Brown was accused of adopting a “Walter Mitty” approach to the banking crisis on Wednesday night after asserting that his sole regret was a failure to get the rest of the world to adopt his ideas on regulation earlier.

“There was a failure in the American regulatory system. Now I am very happy to say that our regulatory system has been a better system,” the prime minister told his monthly press conference. “My regret is that I failed over these years [the past decade] to persuade people – with sufficient force – that our proposals should have been implemented after the Asian crisis.”