President Donald Trump has said he’s “looking forward” to the prospect of sitting down with Special Counsel Robert Mueller. But according to a New York Times report Monday, his private legal team is vehemently urging him to decline any invitation to talk to Mueller.

Negotiations are continuing. But constitutional law experts told TPM that if the White House does choose defiance and Mueller responds with a subpoena, it would likely set up a high-stakes legal showdown—one in which the special counsel might have the upper hand.

A decision by the White House to reject Mueller’s request for a voluntary interview would signal a clear shift in the Trump legal team’s game plan from cooperation to delay.

“If they’re sort of pushing Mueller into a corner where he has to file a subpoena and Trump refuses to comply with the subpoena, they’re switching tracks to a whole new strategy of delay,” said Jens Ohlin, an executive privilege expert at Cornell Law School. “They just want to prevent Mueller from completing his investigation. Which on the one hand is bad for Trump because it keeps the Russia investigation hanging over his head in perpetuity. But, on the other hand, it keeps Trump away from Mueller, and keeps him out of any kind of danger.”

The Times reported that the legal team is split. White House lawyer Ty Cobb is reportedly continuing to argue for full cooperation while Trump’s private attorneys, Jay Sekulow and John Dowd, who is leading discussions with Mueller’s office on the issue, are arguing against a sit-down interview. Trump frequently makes false statements, and Sekulow and Dowd are concerned that talking to Mueller could expose him to charges of lying to investigators, the Times reported.

Asked for comment, both sets of lawyers sent TPM the same statement: “The active discussion between the OSC and the president’s personal lawyers regarding how and under what terms information will be exchanged are understandably private.”

If Trump ultimately declines an interview with Mueller, things could escalate quickly, legal experts said.

Mueller’s team would likely issue a subpoena asking a court to compel the president to appear before the grand jury. Trump might then comply and take the stand, where he could take the politically risky step of pleading the Fifth or telling the jury he does not recall the answers to key questions. More likely, Trump’s legal team would move to quash the subpoena, arguing that a sitting president shouldn’t be required to take time and resources away from his official duties to be questioned in an ongoing criminal investigation, and that Mueller’s queries extend beyond his mandate to investigate Russian interference in the 2016 election.

After a round of litigation in district court, the matter would likely then go to the D.C. Court of Appeals and all the way up to the U.S. Supreme Court.

History offers some pointers on the legal question of whether the president can be forced to testify in civil or criminal litigation. But past commanders-in-chief have either left office before doing so, as Richard Nixon did in the midst of the Watergate scandal, or ultimately agreed to voluntary interviews, as Bill Clinton did with the Paula Jones sexual harassment case and George W. Bush did during the Valerie Plame affair.

Randall Samborn, a spokesman for Special Counsel Patrick Fitzgerald’s investigation into the Plame leak, said the closest precedent was the 1974 US v. Nixon Supreme Court ruling that forced the former president to comply with a special prosecutor’s subpoena to turn over his Oval Office tapes.

The Nixon ruling “makes it compelling for Mueller to obtain presidential testimony under the theory that nobody is above the law, which I think is pretty sound,” Samborn told TPM. “But I also think there continue to be arguments that can and will be made that [special counsel] questioning can’t be open-ended and has got to be narrowly tailored.”

“There has to be specific material in mind that’s unattainable in other ways,” Samborn added. “So I do see it as shifting the burden on Mueller to have to justify the necessity.”

Matters touching on obstruction of justice and Trump’s state of mind would qualify, legal experts told TPM. Those topics are critical to Mueller’s investigation and can only be answered by the president himself, superseding any claims of executive privilege.

“I’m not sure how he could invoke a privilege that would categorically shield him from at least entertaining some questions,” Steve Vladeck, a constitutional law expert at the University of Texas School of Law, told TPM.

Past presidents have argued that there’s a legitimate need to maintain the confidentiality of their executive duties. But those arguments may not be in play here, Vladeck noted. The Times reported that Trump’s attorneys are instead concerned that this particular president will lie or contradict himself under oath, as he so often does in public.

“It’s like self-protection as opposed to institutional preservation,” Vladeck said. “That’s why I think if or when this gets into court the odds are still on Mueller’s side.”

But even if refusing to testify might not be a winning legal strategy, it could make sense politically for Trump. The president’s allies can continue to argue that Mueller is luring him into a perjury trap, knowing that he has a penchant for misstatements and outright falsehoods.

“It’s a way of explaining away why he’s not going to be transparent,” Ohlin said.

And by attacking the credibility of the FBI, DOJ, and Mueller investigation, Trump’s defenders can make the case that there is no reason for him to cooperate with what they argue is a fundamentally compromised probe.

“They’re creating a second pathway by saying, ‘We thought it would be over but it’s not, so clearly it’s an investigation run amok,’” Samborn said. “‘We have no choice but to litigate whether this is even necessary.’”

“It’s like rolling the dice,” Samborn added. “What do they have to lose?”