WASHINGTON — Senate Republicans are intent on scrapping the Affordable Care Act’s requirement that Americans get health insurance, targeting a repeal of the individual mandate to help finance deep tax cuts in their tax overhaul.

The surprise renewal Tuesday of the failed effort to scrap the law’s mandate came a day after President Trump renewed pressure on Republican lawmakers to include the repeal in their tax legislation. It has sharp political stakes for Trump, who lacks a major legislative achievement after nearly 10 months in office.

The move by Republicans on the Senate Finance Committee upended the debate over the tax measure just as it was inching closer to passage following months of fine-tuning and compromise. It turned the debate into an angry partisan referendum on health care and the Affordable Care Act.

Republican efforts to dismantle the law collapsed this past summer as moderate Republicans joined with Democrats in rejecting the repeal – a bitter disappointment for Trump, who lashed out at Senate Republicans for failing. Adding the repeal of the mandate to the tax measure would combine two of Trump’s legislative priorities.

Beyond Trump’s prodding, the repeal move also was dictated by the Republicans’ need to find revenue sources for the massive tax-cut bill, which calls for steep reductions in the corporate tax rate and elimination of some popular tax breaks.

“We are optimistic that inserting the individual mandate repeal would be helpful; that’s obviously the view of the Senate Finance Committee Republicans,” Majority Leader Mitch McConnell, R-Ky., told reporters.

The “Obamacare” mandate requires most people to buy health insurance coverage or face fines. Without being forced to get coverage, fewer people would sign up for Medicaid or buy federally subsidized private insurance. Targeting the mandate in the tax legislation would save an estimated $338 billion over a decade, which could be used to help pay for the deep cuts.

The Congressional Budget Office has estimated that repealing the requirement that people buy health coverage would mean 4 million additional uninsured people by 2019 and 13 million more by 2027.

It “will cause millions to lose their health care and millions more to lose their premiums,” said Sen. Ron Wyden of Oregon, the senior Democrat on the Finance Committee, when the panel reconvened to work on the tax bill and word came of the Republicans’ move on the mandate.

Feeling ambushed without advance notice, minority Democrats exploded in anger.

The completed House tax bill, pointed toward a vote in that chamber Thursday, does not include repeal of the health insurance mandate. Trump plans an in-person appeal to House Republicans before the vote.

To win over moderate Senate Republicans to the tax legislation, the Senate may take up at the same time a bipartisan compromise to shore up health care subsidies, Sen. John Thune, R-S.D., indicated Tuesday. Thune is a member of the Finance panel.

Outside Congress, as word spread of the Senate Republicans’ intention, major organizations representing insurers, doctors and hospitals urged lawmakers to keep Obamacare’s unpopular requirement that most Americans have health insurance – at least for now.

Ending the “individual mandate” would prompt healthy people to leave the insurance market in droves, driving up premiums, the groups argued in a letter Tuesday to congressional leaders.

Republican Sens. Rand Paul of Kentucky and Tom Cotton of Arkansas had pushed for the repeal in the tax bill just months after Republican efforts to dismantle the 2010 health care law had collapsed in the Senate.

“Repealing the mandate pays for more tax cuts for working families and protects them from being fined by the IRS for not being able to afford insurance that Obamacare made unaffordable in the first place,” Cotton said in a statement.

Congressional Republicans projected confidence earlier in the day about delivering the legislation.

“This bill will make things better for hard-working Americans,” House Speaker Paul Ryan, R-Wis., told reporters.

House Republican leaders rallied support with the rank-and-file at a closed-door meeting.

Earlier in the Senate panel’s work on the bill, the Democrats complained that the bill would enable U.S. corporations with foreign operations and wealthy individuals and families to exploit loopholes to skirt millions in taxes.

On Monday, a nonpartisan analysis of the Senate bill showed it would increase taxes for some 13.8 million moderate-income American households.

Promoted as needed relief for the middle class, the House and Senate bills would deeply cut corporate taxes, double the standard deduction used by most Americans and limit or repeal completely the federal deduction for state and local property, income and sales taxes. Republican leaders in Congress view passage of the first major tax revamp in 30 years as imperative for the Republican Party to preserve its majorities in next year’s elections.