WASHINGTON — A former attorney general, John Ashcroft, confirmed the Bush administration was sharply divided over the legality of President Bush’s most contentious eavesdropping work, the chairman of a congressional panel said yesterday.

“It is very apparent to us that there was robust and enormous debate within the administration about the legal basis for the president’s surveillance program,” The House Intelligence Committee chairman, Rep. Silvestre Reyes, a Democrat of Texas, told reporters after a closed-door meeting with Mr. Ashcroft.

The point is critical to two matters being considered in the Democratic-controlled Congress: one is the House and Senate Intelligence committees’ ongoing review of 1978 Foreign Intelligence Surveillance Act, which includes an extensive examination of the president’s warrantless eavesdropping program.

The other is the House and Senate Judiciary Committees’ parallel examinations of current Attorney General Gonzales’s service to the administration. Under that probe, a former deputy attorney general, James Comey confirmed that Gonzales, then White House counsel, tried to pressure him and a critically ill Mr. Ashcroft to certify the legality of the wiretapping program.

Messrs. Comey and Ashcroft, who was in intensive care during Mr. Gonzales’s 2004 hospital visit, refused to comply.

Also yesterday, the Senate Judiciary Committee authorized — but did not issue — subpoenas to Mr. Gonzales and to the custodian of records at the Executive Office of the President for all administration documents on the legality of the program. The panel approved giving its chairman, Senator Leahy, a Democrat of Vermont, authority to issue the subpoenas, 13–3. Senator Specter of Pennsylvania, Senator Hatch of Utah, and Senator Grassley of Iowa voted with the Democrats.