HUNTSVILLE, ALA., JUNE 20 -- President Bush, cheering from the sidelines, today defended his spokesman's efforts to highlight the role of Democrats in the collapse of the savings and loan industry but declined to join directly in the growing political fight over responsibility for the scandal.

Bush said he would not "pour fuel" on the political fire surrounding the crisis and its cost to taxpayers during a news conference in which he also defended his opposition to legislation mandating that firms provide unpaid leave to employees for childbirth, adoption, or serious family illness. He favors such leave, he said, but only on a voluntary basis.

The news conference came on a day in which Bush also began a drive to get full funding for his proposed manned space mission to Mars.

In an unusually harsh attack Tuesday, White House press secretary Marlin Fitzwater named several Democrats he said bore responsibility for the collapse of the thrift industry and said if the Democrats want to make a political issue of the "sorry mess," the White House "is ready to play."

Asked today if he was trying to shift blame for the thrift debacle to Democrats, Bush said, "You're almost getting me into the fight by the way you ask the question, but . . . I am not going to."

Defending Fitzwater, Bush said his press secretary has simply spotted "a couple of shots across my bow from certain distinguished members of the United States Senate, and decided not to acquiesce in those attacks." What Fitzwater said, Bush added, "was appropriate."

Bush said his job is to protect the depositors in thrifts and then to prosecute lawbreakers. Many Democrats have accused the administration of going too slow and too easy on those who gained in the crisis.

In an apparent attempt to limit the political damage from such charges, Bush will hold a news conference Friday with Attorney General Dick Thornburgh and Treasury Secretary Nicholas F. Brady on savings and loan prosecutions, a Justice Department spokesman said. Thornburgh has also ordered all 93 U.S. attorneys to come to Washington that day to discuss savings and loan cases and to attend the news conference, a spokesman said.

At his news conference here, Bush declined to link the deregulation policies of his or the Reagan administration with loan policies that caused the collapse of savings and loans across the nation. He acknowledged only that some of the loans showed "excesses" and were "foolish and ill-advised." But, he said, "I don't want to argue in favor of re-regulating the industry."

On the parental leave issue, Bush denied his threat to veto the legislation is a violation of a campaign pledge. During the campaign, Bush told a women's group, "We need to assure that women don't have to worry about getting their jobs back after having a child or caring for a child during serious illness."

Bush said he just rechecked that pledge this week "and it did not go to what they call mandated benefits." He said he supports collective bargaining agreements to allow such leaves.

Asked what workers should do when their employers will not allow such leaves, he said, "You've got to keep working for them until they do. . . . "

Bush used the Marshall Space Flight Center here as the backdrop to warn Congress that he will fight for $300 million in seed money to pay for the early stages of his proposed manned mission to Mars, which is targeted for the year 2019.

A House Appropriations subcommittee last week cut the administration's space request by $300 million. The cut, the White House maintains, included funds associated with the first stages of the Mars project.

Without directly attacking Democrats, the president said, "Unfortunately, not everyone on Capitol Hill shares a commitment to investing in America's future." When Bush initially announced the Mars project, he was criticized for not providing adequate funding for his ambitious goal.

Staff writer Sharon Lafraniere contributed to this report.