In a rare defiance of the White House, Democratic House leaders are refusing to pass a new surveillance law before it expires on Saturday. The bill would make permanent an earlier measure expanding government authority to eavesdrop on the international telephone calls and email messages of U.S. citizens without warrants. House Democrats say they want more time to resolve a congressional dispute over a provision granting immunity for telecommunication companies that helped the government spy. The White House is pushing for approval of the Senate version, which includes the immunity. On Thursday, President Bush said he would delay a planned trip to Africa to seek the bill’s approval.

President Bush: “Moments ago, my staff informed the House leadership that I am prepared to delay my departure and stay in Washington with them if it will help them complete their work on this critical bill. The lives of many Americans depends on our ability to monitor terrorist communications. Intelligence professionals are working day and night to keep us safe, and they’re waiting to see whether Congress will give them the tools they need to succeed, or tie their hands by failing to act.”

The White House says failure to pass the law will severely limit U.S. spy efforts at home. Democrats accused the Bush administration of fear mongering. Until a new law is passed, the National Security Agency will have to obtain a court warrant if it wants to spy on a previously unknown target.