WASHINGTON — In a bruising setback, Senate Republican leaders shelved a vote on their prized health care bill Tuesday until at least next month, forced to retreat by a GOP rebellion that left them lacking enough votes to even begin debate.

“We will not be on the bill this week,” Senate Majority Leader Mitch McConnell, R-Ky., told reporters in what was a remarkable reversal of plans to push one of President Donald Trump’s and the GOP’s top priorities through the chamber this week.

“But we’re still working toward getting at least 50 people in a comfortable place,” he said. That’s the number of GOP senators who must back the bill for it to survive, with all Democrats opposed.

“We’re got a lot of discussions going on, and I’m still optimistic we’re going to get there,” he added.

Minutes earlier, McConnell divulged the decision to GOP senators at a private lunch also attended by Vice President Mike Pence and White House chief of staff Reince Priebus.

GOP senators planned to travel to the White House later Tuesday to meet with Trump.

McConnell had hoped to push the measure through his chamber before an Independence Day recess that party leaders fear will be used by foes of the legislation to tear away support.

The bill, which would roll back much of President Barack Obama’s health care law, has been one of the party’s top priorities for years, and the delay is a major embarrassment to Trump and McConnell. At least five GOP senators — conservatives and moderates — have said they would vote against even beginning debate, and the bill would be derailed if just three of the 52 Republican senators voted against it.