Wilmer Cutler Pickering Hale and Dorr partner Jamie Gorelick has stepped back from representing senior White House adviser Jared Kushner on Russia-related inquiries, with Norton Rose Fulbright's Abbe Lowell now Kushner's primary defender in the multiple investigations into Russia's efforts to influence the 2016 US presidential election.

Gorelick (pictured above left) said she is "completing the work" that Kushner – US president Donald Trump's son-in-law – originally hired her to do before Trump took office, such as handling Kushner's ethics compliance, security clearance and other federal disclosures.

The news comes after former WilmerHale partner Robert Mueller (pictured above right) left the US firm this May to take on the high profile role as special counsel investigating potential Russian involvement in Trump's election as president.

"Once Bob Mueller and three of our partners left the firm to form the Special Counsel's Office [at the Department of Justice], we advised Mr Kushner to get independent legal advice whether to continue with us as counsel," said Gorelick. "As [a] result of this process, Abbe Lowell is now responsible for the Russia-related inquiries."

Lowell – who Kushner added to his white-collar team on 26 June – is head of the white-collar group at Norton Rose Fulbright after joining the firm as a result of its recent merger with Chadbourne & Parke.

The shift is especially notable because Gorelick has long withstood intense criticism of her representation of Kushner. Gorelick, a former Clinton administration deputy attorney general, had campaigned for Hillary Clinton and was a frontrunner for the US attorney general job if Clinton had won the presidency.

On a professional level, Gorelick faced questions over whether her work for Kushner in the Russia matter would conflict with Mueller's work at the Justice Department. A conflict could have arisen because Mueller and three others on his team were partners with Gorelick at WilmerHale. However, the Justice Department said it was not a problem.

Gorelick has continued to defend Kushner publicly, providing statements on his behalf to media outlets as recently as last weekend. In one of the meetings her client disclosed, Kushner, former Trump campaign manager Paul Manafort and Trump's son Donald Trump Jr met with a Russian lawyer who had promised damaging information about Hillary Clinton to help the Trump presidential campaign.

Gorelick also represents Ivanka Trump, the president's daughter and Kushner's spouse, on her ethical implications of working with the president, financial disclosures and security clearance process.

Separately, Ty Cobb, a veteran Hogan Lovells partner based in Washington DC, is set to join Trump's legal team as special counsel. His last day at Hogan Lovells will be 30 July.

Bloomberg News, which first reported the move, said he would serve as "traffic cop, enforcer of discipline and public spokesman" for the president's legal team as it grapples with simultaneous congressional and Justice Department investigations into the Trump campaign's Russia contacts, which are consuming the president's politics more every day.

Cobb (pictured right) has worked on white-collar cases for more than three decades. He was previously on Hogan Lovells' executive committee and ran various practices including white-collar criminal litigation, US Securities and Exchange Commission enforcement and congressional investigations and hearings.

The National Law Journal obtained a copy of the email written by Hogan Lovells chair Stephen Immelt announcing Cobb's departure. The email noted that while he has been based in Washington DC since 2005, "his colleagues and friends know that he has been working legal magic somewhere exotic more often than he has been in the office".