Key senators have reached a deal “in principle” for Donald Trump Jr. to appear before the Senate Judiciary Committee.

Sen. Dianne Feinstein Dianne Emiel FeinsteinBiden leads Trump by 12 points among Catholic voters: poll Names to watch as Trump picks Ginsburg replacement on Supreme Court McConnell says Trump nominee to replace Ginsburg will get Senate vote MORE (D-Calif.) said Thursday that she had reached the agreement with Sen. Chuck Grassley Charles (Chuck) Ernest GrassleyGardner signals support for taking up Supreme Court nominee this year Grassley, Ernst pledge to 'evaluate' Trump's Supreme Court nominee McConnell digs in on vow to fill Ginsburg's Supreme Court seat MORE (R-Iowa), the panel’s chairman.

Feinstein, the top Democrat on the committee, said the two senators have a deal “in principle.”

ADVERTISEMENT

She stopped short of saying that she and Grassley agreed that Trump Jr. should be subpoenaed, but noted the two had previously agreed to subpoena President Trump Donald John TrumpBubba Wallace to be driver of Michael Jordan, Denny Hamlin NASCAR team Graham: GOP will confirm Trump's Supreme Court nominee before the election Southwest Airlines, unions call for six-month extension of government aid MORE’s former campaign chairman, Paul Manafort.

“If you ask me have we agreed on a subpoena, I believe, you know, if you're not going to attend I would vote to subpoena ... and that's the case for Manafort, we have agreed on a subpoena," Feinstein told reporters.

Spokesmen for Feinstein and Grassley didn't respond to a request for comment on what details still need to be worked out on Trump Jr.'s appearance.

Grassley told reporters on Wednesday that they were still discussing Trump Jr. and had an “agreement in principle” on bringing in Manafort.

Feinstein's comments come after she told CNN on Sunday that Trump Jr. would testify publicly before the Judiciary Committee “this fall, I know that for sure.”

Feinstein and Grassley initially subpoenaed him earlier this year to testify publicly before the committee.

But his legal team cut a deal with the Judiciary Committee “to negotiate to provide the committee with documents and be interviewed by committee members and staff prior to a public hearing.”

Trump Jr. completed a five-hour interview with Judiciary Committee staffers earlier this month, where he was asked about his meeting last year with a Russian lawyer promising dirt on then-Democratic presidential nominee Hillary Clinton.

Grassley has said that he expects both Manafort and Trump Jr. to testify publicly eventually. Democrats have stressed that they want Trump Jr. to testify publicly and under oath.

The Judiciary Committee is investigating Russia's meddling in the 2016 presidential election, as well as potential political interference into FBI investigations and former FBI Director James Comey’s firing.