Former CIA Director John Brennan John Owen BrennanJournalism or partisanship? The media's mistakes of 2016 continue in 2020 Comey on Clinton tweet: 'I regret only being involved in the 2016 election' Ex-CIA Director Brennan questioned for 8 hours in Durham review of Russia probe MORE on Tuesday said Republicans would have to come forward after special counsel Robert Mueller Robert (Bob) MuellerCNN's Toobin warns McCabe is in 'perilous condition' with emboldened Trump CNN anchor rips Trump over Stone while evoking Clinton-Lynch tarmac meeting The Hill's 12:30 Report: New Hampshire fallout MORE's investigation ends in order to put the country and the law "above any one person" — President Trump Donald John TrumpBiden on Trump's refusal to commit to peaceful transfer of power: 'What country are we in?' Romney: 'Unthinkable and unacceptable' to not commit to peaceful transition of power Two Louisville police officers shot amid Breonna Taylor grand jury protests MORE included.

In a tweet, Brennan alluded to “Watergate heroes” and said the GOP must follow suit with the special counsel probe by prioritizing “country, fellow citizens & the law.”

ADVERTISEMENT

"When the Special Counsel’s work is done, the Republican Party must have its modern-day equivalents of Watergate heroes—Howard Baker, Elliot Richardson, Bill Ruckleshaus, John Dean—who will put country, fellow citizens, & the law above any one person, including @realDonaldTrump," Brennan tweeted.

When the Special Counsel’s work is done, the Republican Party must have its modern-day equivalents of Watergate heroes—Howard Baker, Elliot Richardson, Bill Ruckleshaus, John Dean—who will put country, fellow citizens, & the law above any one person, including @realDonaldTrump. — John O. Brennan (@JohnBrennan) June 26, 2018

Mueller's team is investigating Russia's role in the 2016 presidential election, as well as possible collusion between the Trump campaign and Moscow.

The president himself has repeatedly decried the probe as a "witch hunt" and a "hoax" intended to undermine his presidency and cast doubt on the legitimacy of his leadership.

Brennan, who served as CIA director throughout former President Obama's second term in office, has been highly critical of Trump, particularly over his attacks on the U.S. intelligence community and Mueller's investigation.

Brennan's tweet came hours after Bloomberg News reported that Mueller's investigation will focus more intensely in the coming months on allegations of coordination between the Trump campaign and Russia.