Banks may have to hold more capital to protect the taxpayer

The central bank said that banks’ required leverage ratio - the minimum amount of capital they must hold relative to their exposure to loans that could fall in value - could rise to up to 4.95 per cent from 2019, from 3 per cent now.

That means banks would need to hold £1 of capital for every £20 they lend, compared to £1 for every £33 under current leverage rules.

“The Committee believes that its proposals for the design and calibration of the framework will lead to prudent and efficient leverage ratio requirements,” Governor Mark Carney said in a letter to Chancellor George Osborne.

Mr Osborne needs to approve the proposals, and said in response that there would need to be further consultation with banks on the impact of a higher leverage ratio.

The BoE set a complex calculation for the leverage ratio, whereby the minimum level will be based on several factors, including the size of the bank, where Britain is in the credit cycle, and other issues that have not been finalised.

As a result, the minimum leverage ratio for most banks is likely to be far lower than 4.95 per cent. If the economy is regarded as weak and lending prudent, the leverage ratio would only go as high as 4.05 per cent.

Banking sources had expected the ratio to be increased to between 4 per cent and 5 per cent, which analysts said banks can adapt to as long as they had several years to reach it.

The BoE’s proposal is the latest in a series of steps since the financial crisis aimed at making banks protect themselves better against future risks.

Banks have argued that Britain is going too far beyond global rules, and that forcing them to hold excess capital reduces their profits, pushes up the cost of lending and could cut the amount of credit available to home-buyers and companies.

The BoE says safer banks will find it cheaper to raise funds and argues that large banks effectively receive a public subsidy because investors think taxpayers will step in to stop them failing.