REUTERS/Brendan McDermid

Paul Krugman slammed President Trump for threatening 25% tariffs on European vehicles and auto parts as they posed potential risks to national security.

The Nobel Prize-winning economist and New York Times columnist also criticized Trump's refusal to turn over to Congress a report about an investigation into the national-security risks.

"Pretty sure that's just plain illegal," Krugman tweeted. "Congress ... didn't make him a dictator free to set tariffs wherever he likes without even offering an explanation."

Visit Business Insider's homepage for more stories.

Paul Krugman blasted President Donald Trump on Wednesday for threatening 25% tariffs on European vehicles and auto parts as they posed potential risks to national security.

"That's absurd, and a clear abuse of presidential power," the Nobel Prize-winning economist and New York Times columnist tweeted.

Krugman also criticized Trump's refusal to share with Congress a report outlining his administration's investigation into the national-security risks in question. Congress demanded the White House turn over the report in a spending bill last month, the New York Times reported.

"Pretty sure that's just plain illegal," he tweeted. "Congress ceded some trade policy to the executive branch, but it didn't make him a dictator free to set tariffs wherever he likes without even offering an explanation."

"Every time you think you've grasped the awfulness of the Trump administration, you discover new frontiers of contempt for rule of law," Krugman added.

Trump threatened the tariffs in May 2019, but soon ordered a six-month review of the matter to leave more time for trade talks. He declared that tariffs were still on the table at the World Economic Forum in Davos, Switzerland on Tuesday.

"We expect to be able to make a deal with Europe," Trump said. "And if they don't make a deal, we'll certainly give that very strong consideration."

The Justice Department argued that withholding the report falls within Trump's powers as president, and releasing it "would risk impairing ongoing diplomatic efforts to address a national-security threat" and could interfere with White House deliberations on the issue.

A spokesman for Republican Sen. Chuck Grassley told the Times that the Justice Department's opinion "doesn't seem to have much merit on its face. The law as passed by Congress is clear."

Trump has frequently butted heads with Krugman during his presidency. He recently accused the economist of giving "flawed advice," while Krugman has called him "immature and incompetent" and an "enemy of the people."

NOW WATCH: A big-money investor in juggernauts like Facebook and Netflix breaks down the '3rd wave' firms that are leading the next round of tech disruption