Trump says Gavin Newsom's clean energy deal with UK 'inappropriate'

President Donald Trump reignited his long-running feud with California Gov. Gavin Newsom on Monday, blasting the Democrat for cutting a new clean energy deal with the United Kingdom.

Trump branded Newsom a “loser” and mocked him as “Gavin Newscum,” telling Politico it was “inappropriate for [the UK] to be dealing with him.”

“The worst thing that the U.K. can do is get involved in Gavin,” Trump declared to the outlet.

The president was reacting to a memorandum of understanding that Newsom signed in London with UK Energy Secretary Ed Miliband to boost cooperation on clean energy.

The agreement is designed to accelerate investment, scale up clean energy technologies, and expand export opportunities for British firms in California’s market.

Newsom, who is believed to be gearing up to run for US president in 2028, was in London Monday to ink the deal as part of a broader diplomatic swing through Europe, where he has been meeting with leaders to discuss climate policy.

Trump unloaded on Newsom in blunt terms, telling Politico: “Gavin is a loser. Everything he’s touched turns to garbage.”

He added: “His state has gone to hell, and his environmental work is a disaster.”

Referring to California’s trajectory under Democratic leadership, Trump said: “People are leaving.”

He warned the UK that partnering with Newsom would backfire. “If they did to the UK what he did to California, this will not be a very successful venture,” Trump said.

The president also mocked the governor’s infrastructure record, asking: “How has he done with the railroad? How has he done with the various things he’s building?”

Newsom fired back at Trump in a statement to The Post.

“Donald Trump is on his knees for coal and Big Oil, selling out America’s future to China,” a spokesperson for the governor said.

“Governor Newsom will continue to lead in his absence. Foreign leaders are rejecting Trump and choosing California’s vision for the future,” the statement continued.

The Post has sought comment from the White House and Newsom’s office.

Trump has repeatedly portrayed California as a cautionary tale of Democratic governance.

The president has frequently pointed to California’s long-delayed high-speed rail project, noting that the multibillion-dollar effort has faced repeated cost overruns and construction delays since voters first approved it more than a decade ago.

Trump has also seized on recent population declines in the state — driven in part by high housing costs and out-migration — to argue that residents are leaving because of Democratic policies.

Newsom, in turn, has positioned himself as one of Trump’s most outspoken Democratic antagonists through social media posts mocking the president and the administration.

During Trump’s presidency, California has sued the administration dozens of times over environmental rollbacks, immigration enforcement and health care policy.