National Australia Bank, which owns Clydesdale Bank and Yorkshire Bank, said it would not require government help if it was required to bolster its capital ratios along with other UK banks.

The bank, which has 2.6m UK customers, said its operations had a core tier one capital ratio of 7.6 per cent but had no indications that it would need to raise more capital. Last week the British government announced that UK banks would have to recapitalise and bolster their capital ratios – either through private sources or by having the government underwrite a placing.