Sen. Trent Lott (R-Miss.) yesterday lashed out at the White House for undermining his campaign to remain Senate Republican leader, as pressure mounted on him to step down.

On a day when Sen. Lincoln D. Chafee (R.I.) became the first Senate Republican explicitly to call for his ouster, Lott struck back at the White House for leaking negative comments about him in recent days.

"There seems to be some things that are seeping out [of the White House] that have not been helpful," Lott told reporters in Biloxi, Miss. He also voiced his concerns in a phone call with White House Chief of Staff Andrew H. Card Jr., Republican sources said.

Lott's friends say he is upset at the White House not only for refusing to support him as leader, but also for what they regard as behind-the-scenes efforts to push him out. Lott, on several occasions in the past two years, has risen to President Bush's defense, most recently in the debate over authorizing the use of force to depose Iraqi President Saddam Hussein.

White House spokesman Ari Fleischer yesterday denied that Bush or his aides are trying to undermine Lott's bid to remain leader. But numerous White House officials and top presidential advisers have told The Washington Post in recent days that the Mississippian has become a hindrance to the Republican Party's goals, and should be replaced.

If Lott survives, Bush might have a harder time moving his agenda through the Senate, Republicans say, because Lott is unlikely to forget the president's sharp rebuke on Dec. 12 and the White House's subsequent signals of its displeasure. While the president himself remained silent on the issue for yet another day, his brother and Secretary of State Colin L. Powell spoke out. Florida Gov. Jeb Bush (R) told reporters that the Lott controversy is "damaging the party," especially its efforts to reach out to minorities.

Powell, who earlier rebuffed Lott's request for a statement defending him, said he "deplored the sentiments" of Lott's Dec. 5 remarks in support of the pro-segregation presidential campaign of retiring Sen. Strom Thurmond (R-S.C.). "There was nothing about the 1948 election or the Dixiecrat agenda that should have been acceptable in any way to any American at that time or any American now," Powell said.

In his Dec. 5 remarks, which echoed a 1980 comment, Lott said the nation would have been better served if Thurmond had won the presidency in 1948. Thurmond carried four southern states, including Mississippi.

Meanwhile yesterday, Rep. J.C. Watts (Okla.), Congress's only black Republican, reversed field after defending Lott on national TV on Sunday. Appearing on CNN, Watts suggested that Lott not try to keep his leadership post. "I can tell you that if it was me, I would not put my family nor my grandchildren nor my party through that," said Watts, who has been advising Lott this week.

Also calling for Lott to step aside yesterday was religious broadcaster Jerry Falwell. While taping the TV show "America's Black Forum," Falwell said Lott's Dec. 5 statements "were indefensible. . . . By staying on, he's compromising the president's agenda."

Bush, after helping Republicans win back the Senate this fall, has considerable clout among GOP senators, particularly those elected this year and those facing reelection in 2004. But two key senators, both of whom insisted on anonymity, said the clandestine anti-Lott campaign by some White House officials is backfiring.

"The backlash has started," said one senator, who is leaning toward voting for Lott for leader at the Jan. 6 meeting scheduled to address the issue. "We were elected, we are senators and we want to pick our own leader."

Chafee joined Sen. Don Nickles (Okla.), Lott's deputy for the past six years, as the only Republican senators who have strongly suggested, or said outright, that Lott should step aside.

"The only way to have a change, in my opinion, is for the White House to come in here and say to Majority Leader Trent Lott, 'It's time for change,' " Chafee told reporters in his state.

Lott, working the phones from Mississippi, says he has no plans to resign and believes he can survive a vote by his colleagues. He would need 26 votes to survive, and, based on what senators are saying publicly, he has a chance.

The following senators have said they will vote to keep Lott as their caucus leader: Mitch McConnell (Ky.), Rick Santorum (Pa.), Arlen Specter (Pa.), Orrin G. Hatch (Utah), Mike DeWine (Ohio), Ted Stevens (Alaska) and John Ensign (Nev.). DeWine said several others shared their belief that "one incident where he made a very stupid statement should not ruin his career."

Sen. Peter Fitzgerald (R-Ill.), who a few days ago said he would support Lott, backtracked yesterday and declined to indicate how he would vote. Given that Lott won the leadership job unanimously in a vote last month, the silence of so many senators underscores the trouble he faces.

Lott appears to be helped by the absence of a robust challenger. Nickles would like to run, but several GOP senators said he has hurt his chances by calling Sunday for the new leadership election, which was seen by many colleagues as opportunism. Nickles had wanted to challenge Lott well before the controversy, but he couldn't build enough support.

Sen. Bill Frist (Tenn.), who some see as a fresh face for the party, is a favorite of many White House officials and GOP senators, but he isn't eager to run, his aides say. Frist would run only if recruited by senior Republicans, his friends say.

Speaking to reporters in Biloxi, Miss., embattled Senate Republican Leader Trent Lott (Miss.) criticized negative leaks from the White House. "There seems to be some things that are seeping out that have not been helpful," he said.