WASHINGTON — Republican divisions over health care multiplied Monday as President Donald Trump pressured GOP senators to act quickly, and Vice President Mike Pence suggested they might have to revert to a straightforward “Obamacare” repeal if they can’t agree on an alternative.

Consensus on a replacement seemed more remote than ever as senators returned to the Capitol from a Fourth of July recess. Some lawmakers spent the break facing critics of Senate Majority Leader Mitch McConnell’s bill, or voicing criticism of their own. But Sen. John Cornyn of Texas, the No. 2 Republican, told reporters that a revised bill would be unveiled this week, and “the goal continues to be to” vote next week.

McConnell abruptly postponed a vote last month, lacking GOP support for legislation he wrote largely in secret.

To succeed, the new legislation will have to address the concerns of conservatives like Mike Lee of Utah and Ted Cruz of Texas, who want a more full-blown repeal, and moderates like Susan Collins of Maine and Lisa Murkowski of Alaska, who want essentially the opposite, a more generous bill.

McConnell has little room for error as he tries to pass a bill with 50 GOP votes, and Pence as the tie-breaker, in a Senate split 52-48 between Republicans and Democrats. Some GOP senators are questioning McConnell’s partisan approach, and the majority leader himself acknowledged to a home-state audience in Kentucky last week that if he can’t get the job done with Republicans alone, he’ll have to turn to Democrats to shore up the market for individual insurance buyers.

Collins, referring to President Barack Obama’s Affordable Care Act, passed in 2010 without a single Republican vote, told reporters: “I believe that we should not repeat the mistake that President Obama made in passing major legislation with no support from the other party.”

The Republican Party has been campaigning against Obama’s law ever since, but having ridden the issue to control of the House, Senate and the White House, they’re finding it nearly impossible to coalesce around an alternative.

Underscoring the divisions within the GOP, and an occasional communications vacuum between the White House and the Senate, Pence appeared on conservative host Rush Limbaugh’s radio show to rule out working with Democrats.

“The president’s made it very clear. We believe if they can’t pass this carefully crafted repeal and replace bill, do those two things simultaneously, we ought to just repeal only,” and then turn to replacement legislation later on, Pence said, although Trump has at times dangled the prospect of working with Democrats.

Few Republicans on Capitol Hill believe a repeal bill could pass Congress without a replacement.