President Trump on Saturday repeatedly used Twitter to urge Republicans in the Senate to keep trying to reach agreement on a bill to change the Obama health law, threatening to unilaterally end payments the federal government makes to insurance companies that help pay for subsidized health insurance coverage for low income Americans under Obamacare.

"Unless the Republican Senators are total quitters, Repeal & Replace is not dead!" Mr. Trump wrote on Saturday afternoon. "Demand another vote before voting on any other bill!"

Shutting off the subsidy payments, known as "CSR" or cost-sharing reduction, is one of many administrative options open to the Trump Administration. Critics say an end to those payments would immediately create problems on the exchanges, as people would be unable to pay for their insurance.

The President also seemed to threaten to cut off federal money that helps offset some of the health insurance costs of lawmakers and Congressional staff, the same benefit that is given to other federal workers.

Democrats denounced the Trump call to do away with the cost-sharing reduction payments.

Senate Democratic Leader Charles Schumer charged that "every expert agrees that premiums will go up and health care will be more expensive for millions."

Federal officials say seven million people receive cost-sharing payments to pay their insurance premiums under the Obama health law.

As for the part of the tweet that addresses "bailouts for members of Congress," that most likely refers to the payment made on behalf of all federal workers who get health insurance coverage through Uncle Sam, as the feds generally pay 72 percent of their monthly premium.

That's the same for members of Congress and their staffs.

But Republicans argue that no one else who buys insurance coverage through the exchanges gets such help from the federal government - and that this amounts to an illegal setup that favors lawmakers and Capitol Hill staffers.

"President Trump should rescind the rule and make Congress live under the law as written," said Rep. Ron DeSantis (R-FL)

But Democrats - and a number of Republicans - sing a different tune, arguing that lawmakers and staff on Capitol Hill should get employer provided health benefits just like any other federal worker.

"This is a clear threat to Congress: pass my health bill or as punishment I will end health care for you, your staff, and your constituents," wrote Sen. Chris Murphy (D-CT).

For now on health care, the Senate is moving on, unable to generate 50 votes for several GOP health care plans, including a slimmed down "skinny" bill that lost 51-49 early on Friday morning.

Sen. John McCain (R-AZ) - who delivered the key vote that stopped the 'skinny' bill - has told colleagues he will not be coming back soon to Capitol Hill, as he is treated for brain cancer.

That leaves GOP leaders still one vote short - only Sen. Susan Collins (R-ME) and Sen. Lisa Murkowski (R-AK) would be able to switch their vote, and allow a Republican health plan to go forward.

And Mr. Trump has made clear in recent days that he wants Republicans to give it another try.

The Senate is scheduled to be in legislative session the next two weeks, then take a three week break until Labor Day.