WASHINGTON >> House Republicans today released their long-awaited plan for unraveling former President Barack Obama’s health care law, a package that would scale back the government’s role in helping people afford coverage and likely leave more Americans uninsured.

House committees planned to begin voting on the 123-page legislation Wednesday, launching what could be the year’s defining battle in Congress and capping seven years of Republican vows to repeal the 2010 law. Though GOP leaders expect a boost from the backing of the Trump administration, divisions remain and GOP success is not ensured.

The plan would repeal the statute’s unpopular fines on people who don’t carry health insurance. It would replace income-based subsidies the law provides to help millions of Americans pay premiums with age-based tax credits that may be skimpier for people with low incomes. Those payments would phase out for higher-earning people.

The bill would continue Obama’s expansion of Medicaid to additional low-earning Americans until 2020. Beginning then, states adding Medicaid recipients would no longer receive the additional federal funds the statute has provided.

More significantly, Republicans would overhaul the entire federal-state Medicaid program, changing its open-ended federal financing to a limit based on enrollment and costs in each state, a move likely to cause funding cuts.

In perhaps their riskiest political gamble, the plan is expected to cover fewer than the 20 million people insured under Obama’s overhaul, including many residents of states carried by President Donald Trump in November’s election.

Republicans said they don’t have official coverage estimates yet, but aides from both parties and nonpartisan analysts have said they expect those numbers to be lower. Trump has said his goal is “insurance for everybody,” and numerous GOP governors and members of Congress have demanded that people not lose coverage.

House Speaker Paul Ryan, R-Wis., said the bill would “drive down costs, encourage competition, and give every American access to quality, affordable health insurance.”

Spokeswoman Caitlin Oakley said Health Secretary Tom Price “welcomes action by the House to end this nightmare for the American people.”

Solid Democratic opposition is a given.

“Republicans have decided that affordable health care should be the privilege of the wealthy, not the right of every family in America,” said House Minority Leader Nancy Pelosi, D-Calif.

More ominously for Republican leaders, there were signals galore that they faced problems within their own party, including from conservatives complaining that the measure is too timid in repealing Obama’s law.

“It still looks like Obamacare-lite to me,” said Sen. Rand Paul, R-Ky., one of three Senate conservatives who have criticized the GOP bill. “It’s going to have to be better.”

The Republican tax credits, ranging from $2,000 to $14,000 for families, would be refundable, meaning even people with no tax liability would receive payments. Conservatives say that feature creates a new entitlement program the government cannot afford.

Senate Finance Committee Chairman Orrin Hatch, R-Utah, wouldn’t rule out changes by his chamber, where moderate Republicans have grumbled that the measure could leave too many voters uncovered.

“We have a right to look it over and see if we like it or don’t,” Hatch told reporters.

Underscoring those worries, four GOP senators released a letter to Senate Majority Leader Mitch McConnell, R-Ky.

They complained that an earlier, similar draft “does not provide stability and certainty for individuals and families in Medicaid expansion programs.” Signing were Sens. Rob Portman of Ohio, Shelley Moore Capito of West Virginia, Cory Gardner of Colorado and Alaska’s Lisa Murkowski.

Thirty-one states and the District of Columbia expanded Medicaid coverage to 11 million people and accepted beefed-up federal spending for the program. Around half those states have GOP governors, who are largely reluctant to see that spending curtailed.

In another feature that could alienate moderate Republicans, the measure would block for one year federal payments to Planned Parenthood, long opposed by many in the party because it provides abortions. The bill also bars people from receiving tax credits to help pay premiums for plans that provide abortions.

Republicans said they’d not received official estimates on the bill from the Congressional Budget Office. That nonpartisan office’s projections on price tag and coverage could help win over recalcitrant Republicans or make them even harder to persuade.

To prod healthier people to stay covered, insurers would be required to boost premiums by 30 percent for consumers who let insurance lapse.

Tax increases on higher-earning people, the insurance industry and others used to finance the Obama overhaul’s coverage expansion would be repealed.

In a last-minute change to satisfy conservatives, business and unions, Republicans dropped a plan pushed by Ryan to impose a first-ever tax on the most generous employer-provided health plans. Instead, a similar tax imposed by Obama’s law on expensive plans, set to take effect in 2020, would begin in 2025.

Popular consumer protections in Obama’s law would be retained, including insurance safeguards for people with pre-existing medical problems and parents’ ability to keep adult children on their insurance until age 26.