The last-ditch sparring was intense, with both sides trying to buttonhole a dwindling list of undecided lawmakers.

He has turned almost every trip into a none-too-subtle lobbying expedition with one or more undecided or politically vulnerable lawmakers in mind.

Senator Trent Lott of Mississippi, the majority leader, has not said how he will vote, and his decision is expected to sway many undecided lawmakers.

When Republican leaders still came up short of votes, they asked undecided lawmakers what they wanted, then they pulled out their pens and attended to their needs.

So keen, in fact, that on Wednesday Mr. Bush invited about a dozen undecided lawmakers to the White House to urge them to support the bill.

Backers of the project in the Senate concede that support is wearing thin, and the one-sided House vote today is expected to carry considerable weight with undecided lawmakers.

Several undecided lawmakers leaned toward the pact after receiving pledges of protection from foreign farm competition.

Ratcheting up pressure from business groups, the U.S. Chamber of Commerce on Wednesday will launch a new radio campaign targeting about 10 undecided and opposed lawmakers.

Indeed, some undecided lawmakers privately expressed astonishment that Mr. Clinton had stopped short of bluntly demanding their votes.

Mr. Clinton plans to hold a dinner for undecided lawmakers at the White House on Sunday.