Paul Volcker, the former chairman of the Federal Reserve and the architect of the eponymous rule, has expressed disappointment at the political manoeuvring that prevented the strictest version of his proposals making it into the Dodd-Frank Act, while accepting that the compromise was ultimately necessary.

Volcker told the New Yorker, a current affairs magazine, of his dismay on hearing that a strict dollar limit on banks' investment in hedge funds had been dropped from the final bill during the