WASHINGTON >> Conservative Republicans demanded tougher changes today in insurance requirements and Medicaid than the House GOP health care bill proposes and warned they’d oppose the legislation if it isn’t reshaped. The White House signaled an openness to negotiate, but there was resistance from House leaders.

Less than two weeks before the GOP’s showpiece legislation is slated to hit the House floor, the discord underscored the challenge facing top Republicans trying to garner votes for legislation scrapping former President Barack Obama’s health care overhaul.

It also raised questions about whether congressional leaders reluctant to make changes were lagging behind a White House more willing to cut deals. And it illustrated anew the strained relationship between GOP leaders and some conservatives, even as the party tries to deliver one of its highest profile goals.

“If that’s the best that they can do, then perhaps they have a different whip count than I have,” said Rep. Mark Meadows, R-N.C., head of the conservative House Freedom Caucus, suggesting the legislation lacked enough votes to pass.

One conservative priority is quickly halting the extra money Obama’s law gives states to expand the federal-state Medicaid program for 70 million low-income people. The GOP bill would end that additional funding in 2020 except for recipients already in the program, but conservatives want to accelerate that to 2018 to save money.

At the White House, spokesman Sean Spicer suggested President Donald Trump was showing flexibility.

“If someone’s got an idea that can make this legislation more accessible, give more choice to the American people, drive down costs, make it more patient-centered, he wants to listen,” Spicer said. He said Trump is “willing to listen to different individuals” about the Medicaid date but added, “Right now the date that’s in the bill is what the president supports.”

House Majority Leader Kevin McCarthy, R-Calif., told reporters earlier that advancing that date would be “very difficult to do.” Many moderates from the 31 states that expanded Medicaid — adding an extra 11 million people— don’t want the extra money to end sooner.

“Sometimes when you have pushback on one side and the other side from the political spectrum, you might have found the sweet spot,” McCarthy said.

“Our best effort is what you see before us,” said Rep. Greg Walden, R-Ore., a leading author of the legislation.

House Speaker Paul Ryan, R-Wis., has said the bill will pass. GOP leaders are more concerned about unhappy moderates and are coordinating with the White House, said one top Republican who spoke on condition of anonymity in order to discuss tactics.

The GOP bill, approved this week by two House committees, would end Obama’s fines on people who don’t buy insurance and the federal subsidies many who purchase coverage receive. It would instead provide tax credits likely to be less generous for many Americans, curb Medicaid and let insurers charge higher premiums for people whose coverage lapses.

Leading conservatives said they want the bill to erase coverage mandates Obama’s statute imposed, saying their top goal was to reduce consumers’ insurance costs including premiums. That law’s requirements include guaranteed coverage for people, even the seriously ill, and policies that cover 10 specified benefits like maternity and mental health services.

“We’re not going to vote for it until we have a product that we like,” said Rep. Raul Labrador, R-Idaho, a Freedom Caucus member. “The issue is, are we going to drive down the cost of health care.”

The caucus, which claims around 40 members, has been invited to the White House on Tuesday to bowl with budget chief Mick Mulvaney and, lawmakers say, Trump.

McCarthy criticized cries by many conservatives for Congress to vote on a bill Obama vetoed last year that went further in repealing his statute. McCarthy said repealing Obama’s overhaul without approving the GOP legislation “would be just as damaging” as leaving Obama’s law intact and would lead to a collapsed insurance market and higher premiums.

GOP leaders have said their bill omits repealing parts of Obama’s overhaul for procedural reasons.

Their legislation is protected from a Democratic filibuster in the Senate that would take 60 votes to thwart, and there are only 52 GOP senators. To keep that protection, it can’t contain items that don’t directly affect the federal budget, such as insurance policy requirements.

Top Republicans say they are writing a second bill that will make additional changes in Obama’s law. That will need 60 Senate votes, a margin solid Democratic opposition would make unachievable.