Special Counsel Robert Mueller told Donald Trump‘s lawyers last month that he planned to seek an interview with the president.

ROBERT MUELLER LIKELY TO INTERVIEW DONALD TRUMP

Mueller has not yet made a formal request and no date has been set for an interview, but White House officials are assuming that an interview would be the end of the the investigation into Trump. The president’s lawyers are concerned about the move, as allowing a prosecutor to interview a verbose sitting president could be a legal risk. Mueller has already brought charges against four of Trump’s former aides, all for lying to the authorities.

Ty Cobb, the senior White House lawyer on the case, has pledged full cooperation if Mueller ever formally seeks an interview. Cobb insists that the president has nothing to hide in an investigation into if his campaign colluded with Russian operatives to influence the 2016 election.

Trump’s lawyers are expected to ask for ground rules for any conversation. If Trump refuses to cooperate, however, Mueller could issue a grand jury subpoena. The White House has made no official comment on the discussions of an interview.

A source tells the New York Times that Mueller would be most interested in asking questions about former national security advisor Michael T. Flynn and the firing of former FBI director James Comey. These topics could indicate if Trump attempted to obstruct justice by asking Comey to end his investigation into Flynn. After Trump dismissed Comey in May, he told Russian diplomats that doing so had relived a “great pressure” on him.

During past depositions, Trump has shown discipline while under oath. He has also admitted that he uses “truthful hyperbole” and “innocent exaggeration” to make his points. He has not, however, ever been interviewed by a veteran prosecutor like Mueller.

If Mueller decides to proceed, he will have three options of how he wants to interview Trump – written questions, an interview with investigators, or a subpoena to appear before a grand jury. Experts say Mueller will want to speak with Trump directly, and that Trump’s lawyers would not want him to speak before a grand jury, where lawyers are usually not present.