The White House is working on a plan to freeze interest rates on certain subprime home loans, though it faces significant hurdles that could derail its implementation, according to industry executives and others familiar with the situation.

The plan, being discussed by the Treasury department and other regulators, along with mortgage lenders, servicers and investors, is des-igned to forestall a potential crisis when introductory "teaser" rates on nearly $400bn (€272bn, £194bn) of high-risk subprime loans reset higher over the next year.