WASHINGTON — A peeved President Donald Trump browbeat Republican opponents of his party’s reeling health care bill Monday, asserting that his predecessor’s signature overhaul has meant “death” and saying the Senate’s planned faceoff vote is their chance to keep their pledge to repeal it.

Senate Majority Leader Mitch McConnell said he’d call a pivotal vote Tuesday on beginning debate on the legislation, a roll call that seemed likely to go badly for the GOP. He said he’s “made a commitment to the people I represent” to undo President Barack Obama’s health care overhaul, in what seemed a pointed reminder to Republican senators that they’ve made the same vow.

McConnell, R-Ky., did not describe precisely what version of the GOP legislation senators would be voting on. That omission has caused confusion and frustration among some Republican senators, though others have said they expect McConnell to clarify that by the time voting begins.

At the White House, Trump lambasted Democrats who helped enact the 2010 health care law and now uniformly oppose the GOP attempt to scrap and rewrite it.

“They run out and say, ‘Death, death, death,’” Trump said, with a backdrop of families that he said have encountered problems getting affordable, reliable medical coverage because of Obama’s statute. “Well, Obamacare is death. That’s the one that’s death.”

Some Democrats have said the GOP repeal effort would lead to death for patients who lose coverage. The nonpartisan Congressional Budget Office has said various versions of the legislation would mean more than 20 million Americans would become uninsured by 2026.

Trump focused much of remarks on GOP senators. McConnell is nursing a slim 52-48 majority and the possible absence of Arizona Sen. John McCain, who’s battling cancer, which would mean two GOP defections would sink the measure.

“For Senate Republicans, this is their chance to keep their promise. Over and over again, they said, ‘Repeal and replace, repeal and replace.’ But they can now keep their promise,” Trump said.

At least a dozen Republican senators have publicly opposed or criticized the legislation, more than enough to kill it. That’s forced McConnell to step back twice from anticipated votes and to revise his bill in hopes of mollifying unhappy moderates and conservatives.

McConnell’s measure legislation would uproot much of Obama’s law, eliminating its tax penalties on people not buying policies, cutting the Medicaid health care program for the poor and providing less generous health care subsidies for consumers.

He’s revised it once and then said he’d push a vote on legislation simply repealing Obama’s statute. But McConnell and administration officials have also considered additional changes to the repeal-and-replace bill that might lure senators, leaving the focus of Tuesday’s vote uncertain.

Complicating McConnell’s task, Ohio GOP Gov. John Kasich said it would be a mistake for the Senate to move ahead Tuesday “and force a one-sided deal that the American people are clearly against.” Kasich’s stance could make it harder for wavering Sen. Rob Portman, R-Ohio, who’s criticized the measure’s Medicaid cuts, to back the legislation.

Yet in one possible sign of progress by leaders, Portman said it’s “not as important to me” to know what bill McConnell would move to if the Senate votes to begin debate.

Kasich panned the bill for a lack of “bipartisanship, transparency or open dialogue.” In a statement, the 2016 GOP presidential contender said Congress should take no action on recrafting the nation’s health care system until it can “step back from political gamesmanship and come together with a workable, bipartisan plan.”

Yet Portman and other undeclared Republican senators were also being pounded by the White House.

“Republicans have a last chance to do the right thing on Repeal & Replace after years of talking & campaigning on it,” Trump tweeted earlier Monday.

Trump’s contentious tone toward his own party underscored the high stakes as he tries avoiding the specter of Republicans sinking one of his top priorities.