J. David Ake, Associated Press
A cyclist rides across the front plaza of the US Capitol early Tuesday morning Nov. 4, 2014 in Washington.

WASHINGTON — House Republican leaders are looking for more Democratic support ahead of an expected Friday vote on trade legislation, a White House priority, and hope a new negotiating offer could help.

GOP lawmakers offered a concession to Democrats who objected to siphoning money from Medicare to pay for retraining workers displaced by trade agreements. But it was not clear Wednesday whether using a different source of money — fees for various tax violations — would entice enough Democrats to join majority Republicans in passing the measure.

The AFL-CIO, a potent player in Democratic politics, urged lawmakers to reject the GOP-drafted plans for the retraining program, saying the money is insufficient. Many Republicans dislike the program, known as Trade Adjustment Assistance, so numerous Democratic defections could scuttle the entire trade package.

Republican leaders hustled for pro-trade votes Wednesday, but "I don't think they're there yet," said Rep. Mark Amodei, R-Nev., after a closed meeting of House Republicans. Amodei, who is undecided, said his party's leaders need 195 Republicans and figure they will not attract more than 20 or 25 Democrats.

The House has 246 Republicans and 188 Democrats, with once vacancy. If all lawmakers vote, it would take 218 to pass the trade bill.

House Speaker John Boehner, R-Ohio, said trade votes "are never an easy lift around here." But, he added, "We're seeing some positive momentum."

Obama wants the authority to submit trade proposals that Congress can ratify or reject, but not change. If he had it, he would be expected to push the long-negotiated Trans-Pacific Partnership with Japan, Malaysia, Canada, Mexico and several other countries.

The Senate has approved the legislation. But many Democrats worry that trade deals eliminate American jobs. In an unusual alliance with Boehner, Obama has been heavily engaged in securing Democratic votes.

House Minority Leader Nancy Pelosi of California and other Democrats say the Senate bill would use Medicare money to finance the job retraining program. Top House Republicans said they would change the funding source if they needed more Democratic votes, and they did so late Tuesday. The AFL-CIO letter opposing the idea followed on Wednesday.

The changes came after Boehner and Pelosi met privately. Pelosi has been publicly noncommittal on the trade legislation.

Democrats later said many colleagues disliked the proposed process for shifting the jobs program funding. Boehner said he thought such concerns could be addressed by having the House vote first on a relatively minor trade bill that would shift the funding burden away from Medicare. Then, he said, Democrats should have more reason to vote for the trade authority for the president, the main bill in the package.

Strategists on both sides predict a close vote on the entire trade package, which includes the trade authority for the president and the job retraining.

"We feel very comfortable where we are and that's why we're proceeding" said Rep. Paul Ryan, R-Wis., chairman of the House Ways and Means Committee, as he emerged from Wednesday's GOP meeting. He refused to say whether they have the votes.

This story has been corrected to show that it would take 218 votes, not 217, to pass the trade bill.