Ben Bernanke called for fresh efforts to clean up the US banking system on Tuesday, warning that fiscal stimulus measures alone would not be enough to overcome the economic crisis.

Speaking in London, the Federal Reserve chairman said he would like the Obama administration to combine capital injections with a plan to cut troubled assets from bank balance sheets – the idea behind the original version of Treasury secretary Hank Paulson’s troubled asset relief program (Tarp). “More capital injections and guarantees may become necessary to ensure stability and the normalisation of credit markets,” he said.