WASHINGTON (AP) — The Senate Judiciary Committee is poised to vote Thursday on a bill to protect special counsel Robert Mueller's job — legislation that has split Republicans as President Donald Trump has repeatedly criticized Mueller's Russia investigation.

Two Republicans and two Democrats introduced the bill earlier this month as Trump ramped up criticism of the special counsel. Mueller is investigating potential ties between Russia and Trump's 2016 campaign as well as possible obstruction of justice by the president.

The measure under consideration would give any special counsel a 10-day window to seek expedited judicial review of a firing and would put into law existing Justice Department regulations that a special counsel must be fired for good cause. A handful of Republicans have supported it, but most have opposed it, arguing that it is unconstitutional or unnecessary. Senate Majority Leader Mitch McConnell, R-Ky., has argued that Trump won't move to fire Mueller and has insisted he will not hold a full Senate vote on the legislation.

Republicans who support the bill could be at risk of angering Trump and some of his supporters they represent. But the four lawmakers who wrote the legislation — GOP Sens. Thom Tillis of North Carolina and Lindsey Graham of South Carolina and Democrats Chris Coons of Delaware and Cory Booker of New Jersey — are hoping to win enough bipartisan support to move it out of committee. Then, they say, they could try and find enough support in the full Senate to persuade McConnell to change his mind.

With most Democrats on board, the bipartisan group has been working in recent days to gather additional Republican votes. They have been negotiating with Senate Judiciary Chairman Chuck Grassley, R-Iowa, who had floated an amendment that included increased reporting to Congress by the special counsel.

Democrats had initially opposed Grassley's amendment, saying it could undermine the investigation if the special counsel had to reveal too much to Congress during the investigation. But a revised Grassley amendment released Wednesday evening appeared to be a potential compromise, dropping a section that would have required the special counsel's office to report to Congress if the scope of the investigation changed while it was ongoing. The revised amendment would require that notification after the investigation was done, along with a report detailing the investigation's findings and explanations of any charges.

The Grassley amendment would also require notification if a special counsel were removed.

Republicans opposing the bipartisan bill are expected to vote for an alternative resolution that would express a nonbinding "sense of the Senate" that Mueller should be left alone to do his job.

Texas Sen. John Cornyn, the No. 2 Republican in the Senate and a member of the Judiciary panel, endorsed that idea Wednesday, saying it had a more realistic chance of passing than the bipartisan bill. He is expected to propose the resolution at Thursday's vote.

The resolution "may be a way forward because it avoids the unconstitutionality issue on a bill that the president won't sign and the House won't pass," Cornyn said. "So that may be a place for us to land."

Trump's legislative director, Marc Short, said in a broadcast interview Sunday that "as far as I know, the president has no intention of firing" either Mueller or Deputy Attorney General Rod Rosenstein, who oversees Mueller's investigation. Short said he couldn't rule it out in the long term, though, because it's not known "how far off this investigation is going to veer."

The bipartisan group of four senators introduced two separate bills last August when Trump first started to criticize Mueller publicly. That legislation stalled for months, but was revived and the two bills were combined two weeks ago as Trump fumed about a raid of his personal lawyer's office, in an investigation overseen by federal prosecutors in New York.

After the raid, Trump said the Mueller investigation is "an attack on our country" and is "corrupt."

Trump said in a telephone interview Thursday with "Fox & Friends" that he "won't be involved" in the special counsel investigation into Russian election meddling Thursday, but added he may change his mind. Trump called Mueller's probe " a disgrace."

"I am very disappointed in my Justice Department. But because of the fact that it's going on, and I think you'll understand this, I have decided that I won't be involved," Trump said. "I may change my mind at some point, because what's going on is a disgrace."