Energy Secretary Rick Perry has informed President Donald Trump that he intends to step down, the president said Thursday ahead of a campaign rally in Texas.

The resignation notification came just hours after acting White House Chief of Staff Mick Mulvaney told reporters Trump instructed Perry to consider his personal lawyer, Rudolph Giuliani, the lead on all Ukraine policy matters.

[Impeachment panels demand Rick Perry travel, meeting records]

It also comes a day before a Friday deadline for Perry to comply with a House impeachment inquiry subpoena, first issued Oct. 10. The subpoena is seeking documents and communications related to interactions between Trump, Ukrainian officials, a roster of U.S. officials and Giuliani associates.

Perry also reportedly was a key driver in Trump’s Ukraine policy, which prompted House Democrats’ impeachment inquiry.

Perry and his department had denied as late as last week that he was planning to leave his job.

The president, while touring a Louis Vuitton facility in Alvarado, Texas, confirmed Perry’s resignation, according to a pool report from a reporter traveling with him. He said he had planned to announce it at a campaign rally slated for 8 p.m. ET in Dallas.

Trump said Perry likely will remain on the job until late in the calendar year, adding he already has his replacement picked out. The president is fond of acting secretaries and Mulvaney is his acting chief of staff — but he didn’t specify if he will nominate someone to face Senate scrutiny.

“We have the man that we’re going — in this case it’s a man that we’re going to be putting in Rick’s place,” he said. “We’ll be announcing it very shortly.”

Perry’s departure follows publication Thursday of a Wall Street Journal interview in which he criticized Giuliani for pushing what he saw as conspiracy theories — including one Mulvaney repeated Thursday, that a Democratic email server hacked in 2016 resides in Ukraine.

“I don’t know whether that was crap or what,” Perry told the newspaper. “But I’m just saying there were three things that he said. That’s the reason the president doesn’t trust these guys.”

Giuliani, the former U.S. attorney and New York mayor, “didn’t say, ‘They gotta do X, Y and Z.’ He just said, ‘You want to know why he ain’t comfortable about letting this guy come in? Here’s the reason,’” Perry alleged.

He is the latest Cabinet or senior White House official to leave the administration since it took office. But he is the most senior to step down or be fired since the impeachment probe formally began late last month.

Trump was holding a fundraiser in Texas, a state where Perry once was the governor, when Bloomberg News first reported his resignation.

The Senate confirmed Perry, the longest-serving governor of Texas, 62-37 to run the department in March 2017, despite his former pledge as a presidential candidate to eliminate the department.

He took over a highly technical department responsible for overseeing nuclear weapons safety and waste, scientific research, energy projects and a network of national laboratories.

Soon he took to cheerleading for White House policies and sought to sell members of both parties on deep cuts proposed by the White House to energy programs such as energy efficiency and renewables research, as well as to the department’s Advanced Research Projects Agency-Energy, an in-house technology incubator.

“I’m not Pollyanna,” Perry told members of the Senate Energy and Natural Resources Committee at a budget hearing in April, defending the administration’s proposed cuts. “I understand your concerns about particular line items.”

From his perch, Perry, who has been seen as a stabilizing force in a presidential administration that has lurched from resignation to resignation of federal agency heads, traveled abroad often to promote fossil fuel exports — especially natural gas and a specific type, liquefied natural gas, or LNG.

DOE dubbed natural gas as “freedom gas” in some of its public statements. In May, the agency touted an LNG plant in Freeport, Texas slated for construction.

“Increasing export capacity from the Freeport LNG project is critical to spreading freedom gas throughout the world by giving America’s allies a diverse and affordable source of clean energy,” Mark W. Menezes, an under secretary for energy, said in a statement at the time.

On climate change, he often disputed established science in his role, discounting humans’ effect on a warming planet.

During a television interview in 2017, Perry said carbon dioxide from humanity is the primary force behind climate change. “Is the climate changing, is man having an effect on it?” Perry asked. “Yeah, we are. The question should be just how much, and what are the policy changes that we need to make to affect that?”

Widely established climate science and research by federal agencies like NASA, the Pentagon and Perry’s own department have concluded that human activity is the driving force behind climate change.

Ukraine probes

Congressional investigators are scrutinizing Perry’s connections to Ukraine and efforts he made to replace board members of Naftogaz, a state-run natural gas firm there.

Chairmen of the House Intelligence, Oversight and Foreign Affairs committees subpoenaed Perry last week for records about his interactions with Ukrainian officials.

Reps. Eliot L. Engel, D-N.Y., chairman of the Foreign Affairs Committee; Adam B. Schiff, D-Calif., chairman of the Intelligence Committee; and Elijah E. Cummings, D-Md., chairman of the Oversight and Government Reform Committee, sent the subpoenas. Perry had until tomorrow to comply.

“Recently, public reports have raised questions about any role you may have played in conveying or reinforcing the President’s stark message to the Ukrainian President,” the chairmen said in a letter.

“These reports have also raised significant questions about your efforts to press Ukrainian officials to change the management structure at a Ukrainian state-owned energy company to benefit individuals involved with Rudy Giuliani’s push to get Ukrainian officials to interfere in our 2020 election,” it says.

Possible successor

Dan Brouillette, the deputy secretary at DOE, would be expected to carry on much of Perry’s legacy if he assumes control of the department.

A former congressional staffer and political appointee under President George W. Bush, Brouillette has not shown much daylight between his and Perry’s policies.

He backed Perry in an attempt in January of 2018 to force power plants to maintain at least 90 days worth of fuel on-site, a policy that would have benefited coal and nuclear fuel sources.

And he has given vague answers about human-caused climate change. “Quite simply, senator, the climate is changing and we’re all living here so we must have some impact,” Brouillette said at his confirmation hearing.

Like Perry, he has also traveled worldwide to promote U.S. energy sources.

Brouillette led an American delegation to Kazakhstan in August 2017 to research a deal between the countries on nuclear-generated electricity.