WASHINGTON — Senate Republicans ended a demoralizing week on Thursday with their leaders determined to press ahead with a vote to begin debating health care next week, but with little progress on securing the votes and no agreement even on which bill to take up.

With President Trump urging them to move forward on their seven-year quest to erase the Affordable Care Act, Republican senators on Thursday still had not decided whether to revive a proposal to replace former President Barack Obama’s health care law with one of their own, or to simply repeal it and work on a replacement later.

The choice is unpalatable: The nonpartisan Congressional Budget Office said on Thursday that the latest version of the bill to repeal and replace the health law would increase the number of people without health insurance by 15 million next year and by 22 million in 2026. Those figures are the same as the estimates in the budget office’s previous analysis, despite numerous changes to the bill intended to win votes.

On the other hand, if senators opted simply to repeal the existing law, the budget office said on Wednesday, 32 million more people would be uninsured in 2026 compared with current law.