The top Democrat in the Senate promised to hold up the chamber with scores of amendments if Republicans pass a bill that repeals a few big parts of Obamacare.

Senate Minority Leader Chuck Schumer said Thursday that if the "skinny repeal" bill, expected to be brought up Thursday, does not pass, the Senate can move on to the National Defense Act Authorization.

However, if it passes, Democrats would have "an unlimited right after it passes to offer unlimited amounts of amendments."

Senate Majority Leader Mitch McConnell later said that the plan is to bring up the NDAA after the healthcare debate ends.

The Senate narrowly voted Tuesday to start debate on Obamacare repeal but have not coalesced around a replacement plan. While they voted to start debating a House bill to repeal and replace Obamacare, the Senate plans to strip out that bill but doesn't know what it will replace it with.

Votes to replace the House bill with a bill to repeal and replace Obamacare failed, as did a vote to repeal Obamacare without a replacement for two years.

Senate leadership's plan now is to bring up a "skinny repeal" bill that could eliminate only Obamacare's individual and employer mandates and medical device tax. The final text is expected to be released Thursday.

Schumer, of New York, said Wednesday that Democrats will not offer any amendments until the final skinny repeal text emerges.

He bashed the skinny repeal idea on Thursday, saying that neither conservative nor moderate Republicans like it.

"Is this the one plan that finally unites the Republican Senate? A plan that angers everyone?" he asked.

While Republicans aren't happy with skinny repeal, some say they will support it because it could be a vehicle to start negotiations with the House on a new Obamacare repeal bill.

Schumer bashed Republicans aiming to do that.

"You shouldn't be passing a bill you don't support or believe in, that you pray won't become law," he said.

The Senate is debating the underlying House bill. Voting on any amendments offered, a process called vote-a-rama, is expected to start later Thursday. Any lawmaker can offer unlimited amendments.

After the vote-a-rama concludes, the GOP can bring up the skinny repeal bill as a final amendment to the bill.