Mueller reportedly threatened to subpoena Trump if he refused to talk to the special counsel under oath

AP Photo/Evan Vucci

President Donald Trump listens during a meeting with law enforcement officials on the MS-13 street gang and border security, in the Cabinet Room of the White House in Washington on Feb. 6, 2018.

• Special counsel Robert Mueller reportedly threatened President Donald Trump and his legal team that he could subpoena Trump to compel him to answer questions related to the Russia investigation.
• The alleged threat came as Trump's legal team and the special counsel's office were negotiating terms of a one-on-one interview with the president, which, at the time, Trump said he did not want to grant.
• The development sheds new light on the internal wrangling between the special counsel and Trump, as the probe of Russia's interference in the 2016 US election gained new momentum.

The special counsel Robert Mueller threatened President Donald Trump's legal team with a grand jury subpoena in March if Trump refused to voluntarily sit down with prosecutors conducting the Russia investigation.

That apparent threat came during negotiations between Mueller's office and Trump's lawyers, at a time when the president's legal team asserted that they had no obligation to answer questions from Mueller under oath, The Washington Post reported on Tuesday.

Citing two people with knowledge of the conversations, The Post said that John Dowd, the now-resigned attorney who was representing Trump in the Russia probe, snapped back at Mueller's team: "This is not a game," Dowd reportedly said according to the newspaper. "You are screwing with the work of the president of the United States."

The development sheds new light on the internal wrangling between Trump's lawyers and the special counsel over the interview that Mueller wants with the president.

Over the last year, Trump has expressed his willingness to sit down with Mueller, but changed course last month after properties belonging to his longtime personal attorney, Michael Cohen, were raided by the FBI in an unrelated case.

More recently, those discussions were said to be back on, after Trump hired former New York mayor Rudy Giuliani, a loyal supporter of the president, to join his legal team.

In what some legal experts have viewed as a key concession to Trump's team, Mueller reportedly offered Trump's lawyers a glimpse at some of the questions he might ask the president during such an interview.

The New York Times published a sampling of those questions on Monday night - some of which get at the collusion question between Trump's campaign and Russian operatives who sought to influence the US election.