Attorney General Maura Healey must defend her probe of ­Exxon Mobil’s climate-change policy in a Texas courtroom hearing that one prominent analyst says shows a federal judge sees “big-time political motives” in her use of power.

The order issued by Judge Ed Kinkeade late last week, could compel a law-enforcement officer to answer a target firm’s questions in a Dallas courtroom deposition Dec. 13. First Amendment attorney Harvey Silverglate said it’s “very rare” for a sitting attorney general to be ordered to court for a deposition.

“It indicates that the judge suspects big-time political motives,” Silverglate told the Herald, adding he sees Healey’s probe as “political grandstanding …. There is nothing really to be gained here except to embarrass the company. There is no legislation in this country thus far making it a crime to oppose global warming.”

Healey launched her probe of Exxon Mobil’s research in April on the grounds the oil giant was deceiving consumers and investors. Exxon Mobil filed for an injunction to stop her on First Amendment and other grounds. Healey’s attorneys have moved to toss that motion. But last month, Kinkeade, noting that Exxon Mobil suspects Healey was attempting “to satisfy a political agenda,” issued a written ruling saying he needed to know more about what was behind her civil investigation demand before he finds for either side.

“Attorney General Healey’s actions leading up to the issuance of the CID causes the Court concern and presents the Court with the question of whether Attorney General Healey issued the CID with bias or prejudgment about what the investigation of Exxon would discover,” Kinkeade wrote. He noted that Healey, along with New York Attorney General Eric Schneiderman and former Vice President Al Gore, took part in an “AGs United For Clean Power” press conference three weeks earlier, where Healey announced her plan to hold Exxon Mobil accountable.

Schneiderman also has been ordered to Dallas for the Dec. 13 hearing.

Healey’s spokeswoman said in a statement, “We are surprised that the Court has ordered two Attorneys General to appear for depositions in Dallas even though Exxon made no such request. Our office has argued strongly that there is no personal jurisdiction in Texas and have urged the Court to rule on our motion for dismissal. In the meantime, we continue to litigate against Exxon in Massachusetts state court, where this dispute properly belongs, and will fight aggressively to investigate whether Exxon Mobil deceived consumers and investors about the impact of fossil fuels.”

In a court filing earlier this month, lawyers for Exxon Mobil charged, “For nearly a decade, climate change activists and certain plaintiffs’ attorneys have sought to obtain the confidential records of energy companies as a means of pressuring those companies to change their policy positions.” They dismiss Healey’s efforts as a fishing expedition for “ammunition.”

Kinkeade, appointed by President George W. Bush, has to decide whether to enjoin Healey from moving forward in Massachusetts with her probe into whether the $171-billion Texas-based Exxon Mobil Corp. has deceived consumers and investors about the potential environmental hazards of fossil fuel. If Healey prevails, Exxon Mobil would be forced to disclose records ­dating back to 1976 on what — if anything — it knew about global warming and climate change.

Silverglate said Healey could try to appeal being deposed, but doesn’t think she’d win. Still, he said, Judge Kinkeade’s order is so unusual a higher court would likely hear her objections.