A key group of conservative Republicans in the House is threatening to issue a formal statement of opposition to the Obamacare replacement bill — potentially crippling its chances of being passed in its current form Thursday during a scheduled vote by the full House.

The Freedom Caucus is poised to issue that negative statement — which likely would delay the vote — unless the language in the legislation changes dramatically by Wednesday night.

The bill, as currently written, is "going down as of now," said a source familiar with the situation.

There are 25 "hard" no votes against the bill in the conservative caucus, and two more members are leaning toward voting against it, the source said. Republicans hold just 230 seats in the House, so they cannot afford that many no votes if they hope to pass the bill, given that most, if not all, Democrats will oppose it.

Conservative opposition to the bill stems from a belief that it does not go far enough to repeal Obamacare.

The potential move by Freedom Caucus is a slap in the face to Republican leaders and to President Donald Trump, who traveled to Capitol Hill on Tuesday to personally lobby members of the GOP to pass the bill known as the American Health Care Act.

Trump warned caucus members than many of them could lose their seats in Congress next year if they voted against the bill.

On Monday night, GOP leaders made several changes to the bill, most of which were designed to assuage concerns about the legislation by conservative members of the House.