WASHINGTON – The Senate Judiciary Committee chairman, Arlen Specter, said Thursday he is considering legislation to cut off funding for the Bush administration’s secret wiretapping program until he gets satisfactory answers about it from the White House.

“Institutionally, the presidency is walking all over Congress at the moment,” Mr. Specter, a Republican of Pennsylvania, told the panel. “If we are to maintain our institutional prerogative, that may be the only way we can do it.”

Mr. Specter said he had informed President Bush about his intention and that he has attracted several potential co-sponsors. He said he’s become increasingly frustrated in trying to elicit information about the program from senior White House officials at several public hearings.

The amendment amounted to a warning to the White House from a powerful but frustrated Senate chairman.

“I’m not prepared to vote for it myself,” Mr. Specter told reporters.

The move got the White House’s attention, but not its immediate cooperation. Mr. Bush has insisted that the program falls within his authority and has staunchly refused to allow administration officials to answer many of Mr. Specter’s questions.

“The appropriate members of Congress have been and continue to be informed with respect to the Terrorist Surveillance Program,” said White House spokeswoman Dana Perino. “The Administration remains confident that a majority of members of Congress continue to recognize the importance of protecting Americans through lawful intelligence activities directed at terrorists.”

Mr. Specter also agreed with Democrats who say that any of the bills to tighten guidelines for National Security Agency program and increase congressional oversight could be flatly ignored by an administration with a long history of acting alone in security matters.

“It is true that we have no assurance that the president would follow any statute that we enact,” Mr. Specter said. He said he’s considering adding an amendment to stop funding of the program to an Iraq war-hurricane relief bill being debated by the Senate this week and next.

Mr. Specter’s announcement came a day after the House passed an bill 327-96 to dramatically increase spending on intelligence programs. In the process, Republicans blocked an amendment to expand congressional oversight of the NSA’s warrantless surveillance program.

The House Intelligence Committee chairman, Peter Hoekstra, a Republican of Michigan, said allegations that NSA wiretapping operations are abusive or unconstitutional are outrageous and that Congress is committed to vigorous oversight of the program.