In a sweeping rebuke to Wall Street, US regulators said 11 of the nation's biggest banks haven't demonstrated they can collapse without causing broad, damaging economic repercussions and ordered them to show "significant" progress by July 2015.

The Federal Reserve and the Federal Deposit Insurance Corp said bankruptcy plans submitted by big banks make "unrealistic or inadequately supported" assumptions and "fail to make, or even to identify, the kinds of changes in firm structure and practices that would be necessary to enhance the prospects for" an orderly failure. The regulators raised the spectre of slapping banks with tougher capital, leverage and other rules-and even eventually forcibly breaking them up-absent significant progress to address the shortcomings.