Senate Republican leaders head into a difficult fight this weekto win support for their health care legislation after returningfrom a recess where some GOP lawmakers fielded angry complaintsfrom constituents about the measure.

Related: Mitch McConnell may be forced to consider Plan Bfor ACA repeal

Senate Majority Leader Mitch McConnell has made little progresson winning over his party’s holdouts as he negotiates with themover revisions to a bill he proposed last month that combines taxcuts with deep reductions in health spending.

Changes under consideration include ditching a repeal ofObamacare’s tax increases on the wealthy, revising Medicaid cutsand adding more spending to stabilize premium costs in theindividual insurance market, according to a GOP aide who requestedanonymity.

McConnell has little time to make a deal. Republican leadershave said they need to move on to other issues, including atax-code overhaul and next year’s spending bills, if they can’tagree on a health bill before a month-long August break.

For the bill to pass, and Republicans to live up to theirpromise to eliminate President Barack Obama’s signature domesticaccomplishment, they can lose no more than two GOP votes from their52-48 majority amid unanimous Democratic opposition.

Republicans say they’re increasingly pessimistic the GOPlegislation can win approval.

Senator Bill Cassidy of Louisiana said on “Fox News Sunday” thatMcConnell’s original plan is dead and that what happens with therewritten version remains to be seen. He put the odds of passing abill in July at “50-50.”

Given the lack of support for McConnell’s legislation, SenatorJohn McCain of Arizona said on CBS’s “Face the Nation” thatRepublicans should write a new bill and let Democrats offeramendments. “That’s what democracy is supposed to be all about,” hesaid.

McConnell himself took a risk on Thursday by calling for abipartisan health-care plan if the Republican-only bill fails. Hetold an audience in his home state of Kentucky that the AffordableCare Act needs to be altered, as insurers are pulling out of someareas.

McConnell’s message could serve as a warning to holdoutconservative Republicans most ideologically opposed to Obamacare,but the remarks also may give wavering moderates cover to opposethe GOP plan.

The Trump administration is taking a more optimistic view onpassing a bill. The Senate may delay its August recess to finishthe health-care overhaul, White House Chief of Staff Reince Priebuspredicted on “Fox News Sunday.”

McConnell is awaiting estimates from the Congressional BudgetOffice of possible changes to his bill to determine whether theywould increase spending or alter estimates of the number of peoplewho would lose their health coverage. The CBO said the initialproposal from McConnell would cause 22 million fewer Americans tohave health insurance in a decade.

"Discussions about the legislation continue within theconference and with CBO,” said David Popp, McConnell’sspokesman.

Republican leaders are considering axing plans to repeal nearlyall of the tax increases that help finance the Affordable Care Act,said the GOP aide. The GOP health bill may retain a 3.8 percentinvestment tax on high-income earners and a Medicare earned-incomesurcharge on the wealthy.

Medicaid changes

Those two tax increases generate nearly $231 billion in revenueover a decade, according to the Joint Committee on Taxation.Leaving them in place could create a way to cover the costs ofexpanded Medicaid coverage for the poor or other programs demandedby holdout moderate Republicans.

Related: Disability advocates fear impact of Medicaidcuts

There likely will be changes to the Medicaid provisions inMcConnell’s earlier proposal based on feedback from senators, theaide said. These changes are proving to be among the most difficultto negotiate as GOP senators have vastly different requests basedon their states’ needs, the aide said.

The aide said a revised bill probably will boost proposedspending to stabilize premium costs in Obamacare’s insuranceexchanges, where those without employer- or government-providedcoverage can buy individual policies.

McConnell’s earlier legislation includes $50 billion over fouryears to bolster insurance markets, in addition to addedcost-sharing subsidies. It also includes a state innovation pool of$62 billion over eight years that would allow jurisdictions fundingfor high-risk pools, reinsurance and other items.

During the week-long congressional recess, Republican lawmakerswho held public appearances got an earful on the GOP’s bill, whichpolls show has attracted little public support.

‘Stepping on the necks’

At a town hall meeting in Baton Rouge, one Louisiana man toldCassidy that cutting health care for 22 million Americans is akinto “stepping on the necks” of his constituents.

Senator Jerry Moran of Kansas told constituents who expressedopposition to the GOP health plan at a gathering in Palco that hewould demand the bill address the needs of people with pre-existingconditions and lower premium costs. “That’s not where we are withthe legislation pending in the Senate,” he said.

Senator Susan Collins of Maine told the Washington Post after aJuly 4 parade that people were encouraging her to stand against theSenate bill and the House’s version of health legislation thatpassed in May.

“People were thanking me, over and over again,” she told thePost. “‘Thank you, Susan!’ ’Stay strong, Susan!’"

Opioid epidemic

McConnell’s early attempts to win over opponents haven’t worked.GOP leaders agreed more than a week ago to add $45 billion inspending to address the opioid epidemic, a key demand of moderateslike Rob Portman of Ohio and Shelley Moore Capito of WestVirginia.

Related: Opioid prescriptions ebb but addiction, overdosesstill vex U.S.

After a tour of a suburban Cincinnati drug recovery center lastweek, Portman told an Associated Press reporter that the additionof those funds is but a first step. "I’m still concerned about theway in which Medicaid is dealt with in the proposal," Portmansaid.

Republican leaders are considering a provision proposed bySenator Ted Cruz, a Texas Republican, that a group of conservativeGOP senators say could help gain their support. Cruz wants to allowinsurers to offer cheap, bare-bones plans alongside those that meetthe more comprehensive coverage requirements of Obamacare.

Critics in both parties say the proposal would essentially putpeople with pre-existing conditions in the Obamacare insurance pooland allow young, healthy people to buy cheaper plans in a separatepool.

Two Republican aides said GOP leaders asked the CBO to examinethe impact of Cruz’s plan alongside a companion piece that wouldboost money to stabilize the exchanges.

The conservative Club for Growth is calling on McConnell toinclude Cruz’s insurance proposal, and to also repeal Obamacare’snet investment income tax. Without those two demands, the bestresult would be for McConnell to simply seek to repeal Obamacare,Club for Growth president David McIntosh said in a statement.

If McConnell can’t salvage his legislation, “the next bestoption would be to pass a real repeal bill as a standalone,”McIntosh said.

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