After eight hours of debate, House Rules Committee Chairman Rep. Pete Sessions, R-Texas, left, and Rep. Tom Cole, R-Okla., the vice-chair, listen to arguments from committee chairs as the panel meets to shape the final version of the Republican health care bill before it goes to the floor for debate and a vote, Wednesday, March 22, 2017, on Capitol Hill in Washington. (AP Photo/J. Scott Applewhite)
After eight hours of debate, House Rules Committee Chairman Rep. Pete Sessions, R-Texas, left, and Rep. Tom Cole, R-Okla., the vice-chair, listen to arguments from committee chairs as the panel meets to shape the final version of the Republican health care bill before it goes to the floor for debate and a vote, Wednesday, March 22, 2017, on Capitol Hill in Washington. (AP Photo/J. Scott Applewhite) Credit: J. Scott Applewhite

WASHINGTON — The top Republican legislative priority in peril, President Donald Trump dangled possible changes to the health care bill Wednesday aimed at placating conservatives threatening to torpedo the legislation. The White House seemed to make progress after GOP opposition had snowballed a day before a showdown House roll call.

Trump huddled at the White House with 18 lawmakers, a mix of supporters and opponents, Vice President Mike Pence saw around two dozen and House GOP leaders held countless talks with lawmakers at the Capitol. The sessions came as leaders rummaged for votes on a roll call they can ill afford to lose without diminishing their clout for the rest of the GOP agenda.

Most GOP opponents were conservatives asserting that the legislation demolishing former President Barack Obama’s health care law did not go far enough. They were demanding repeal of the law’s requirements that insurers pay for specified services like maternity care and mental health counseling.

In early meetings with Trump and Pence and later discussions with the White House, talks focused on language addressing conservatives’ concerns that those coverage requirements drive up premiums. Details were unclear, but members of the House Freedom Caucus, the hard-line group spearheading the opposition, were expected at the White House early Thursday.

It was initially uncertain if the provision could survive in the Senate or how moderate Republicans would react. Democrats said the language would die in the Senate because that chamber’s rules don’t allow provisions not directly related to the federal budget.

In a count by The Associated Press, at least 25 Republicans said they opposed the bill and others were leaning that way, enough to narrowly defeat the measure. The number was in constant flux amid eleventh-hour lobbying by the White House and GOP leaders.