British regulators are ordering its biggest banks to bolster their balance sheets by 27. 1 billion pounds ($42.1 billion) to prevent a repeat of the 2008 banking crisis.

The Prudential Regulation Authority says Barclays, Lloyds Banking Group and Royal Bank of Scotland account for much of the shortfall. Barclays must boost its capital by 3 billion pounds and state-backed RBS and Lloyds must find 13.6 billion pounds and 8.6 billion pounds respectively.

The report is likely to raise pressure on banks, which are being ordered to hold more capital even as they are being pushed to lend to businesses and families to kick-start the economy.

The banks will be given time to plug their capital holes. Lloyds and RBS have said they won't need to ask investors for more money.