Labour will break up Britain's "big five" banking monopoly by forcing the high street giants to give up branches and open the market to competition, Ed Miliband (pictured) promised yesterday.

Delivering a speech at the University of London, the party leader said a Labour government would impose a US-style cap on the market share that any one bank can have in personal accounts and small business lending.

If the party wins the next general election, government department the Competition and Markets Authority would be instructed to report within six months on how to create a least two new "sizeable and competitive banks" to challenge existing lenders.