Gibson, Dunn & Crutcher litigation co-chair Theodore Boutrous confirmed in a tweet Tuesday that his partner Theodore Olson will not join the legal team representing President Donald Trump.

The Washington Post reported Tuesday that Trump's legal team had reached out to Olson, a former U.S. solicitor general and top national appellate lawyer, “to join forces” as the president confronts special counsel Robert Mueller's probe into Russian interference in the 2016 election.

A source familiar with the law firm's decision-making, who could only speak anonymously, told ALM that Olson declined the invitation Tuesday morning, a day after he was contacted about joining the team.

Olson has top conservative credentials. He was U.S. solicitor general during the George W. Bush administration, after representing Bush at the U.S. Supreme Court in Bush v. Gore.

But he famously teamed up with David Boies, his opponent in Bush v. Gore, to fight California's ban on same-sex marriage.

Joining Trump's legal team could have exposed Gibson Dunn to conflicts. For instance, Boutrous is representing Fusion GPS, the firm behind the so-called Trump dossier.

Boutrous and other attorneys also led the defense in the U.S. Supreme Court of the Deferred Action for Childhood Arrivals program, commonly known as DACA, created by the Obama administration in 2012. Last month, the Trump administration lost its bid in the high court to quickly terminate the immigration program.

Boutrous has been vocal against Trump not only in court, but also on Twitter. In a tweet during the 2016 election campaign, he offered to defend pro bono “anyone Trump sues for exercising their free speech rights.”

This week's overture to Olson by the Trump team is the second time Olson has been approached, after reportedly being contacted last year.

When asked for comment about the latest developments, a firm spokeswoman referred to Boutrous' tweet.