In a series of tweets on Wednesday, Trump called the idea that his campaign worked with Moscow a ‘TOTAL HOAX’.

US President Donald Trump on Wednesday called on Attorney General Jeff Sessions to end a federal investigation into Russian interference in the 2016 presidential election and whether there was any cooperation by his campaign with Moscow.

The Republican president has long complained about the criminal probe into his White House victory but Wednesday’s comment appeared to be his most direct call for shutting down the investigation by special counsel Robert Mueller.

In a series of tweets, Trump called it a “TOTAL HOAX” the idea his campaign worked with Moscow. “This is a terrible situation and Attorney General Jeff Sessions should stop this Rigged Witch Hunt right now, before it continues to stain our country any further,” he said.

Trump also alleged that Mueller is “totally conflicted.” He provided no evidence that the team led by Mueller, a Republican who was appointed by a Republican, is biased against him.

The first trial arising from the probe into Russia‘s role in the election began on Tuesday in Alexandria, Virginia. Trump’s former campaign chairman, Paul Manafort, faces 18 counts of bank and tax fraud charges.

A Department of Justice spokeswoman said the department had no immediate comment on Trump’s tweet about ending Mueller’s probe.

‘He’s panicking’

Democratic legislators criticised Trump for seeking an end to the probe and urged that Congress protect the investigation.

“These kinds of threats are no accident. They reflect a state of mind and an intent to obstruct justice,” said Senator Richard Blumenthal, a member of the Senate Committee on the Judiciary.

“He’s panicking,” Democratic Representative Don Beyer said on Twitter. “Congress must protect Mueller.”

Trump has steadily attacked his attorney general for recusing himself from the Russia probe in March 2017.

Sessions cited his role as a senior adviser to Trump’s presidential campaign and appointed Deputy Attorney General Rod Rosenstein to oversee the investigation.

Rosenstein, in turn, appointed Mueller and is the person with the authority to fire him.

An element of Mueller’s investigation includes whether Trump or anyone in the campaign tried to obstruct justice. The New York Times reported last week the Mueller team was examining negative tweets and statements by Trump about Sessions and former FBI Director James Comey.

US intelligence agencies concluded last year that Moscow meddled in the 2016 presidential campaign to try to tip the vote in Trump’s favour. Moscow has denied such interference, and Trump has denied any collusion by his campaign or any obstruction of justice.

‘Continued frustration’

Trump’s personal lawyer, Rudy Giuliani, said that in his tweet Trump was expressing an opinion long espoused by his team.

“We have been saying for months that it is time to bring this inquiry to an end. The president has expressed the same opinion,” Giuliani told Reuters.

Jens David Ohlin, a law professor at Cornell University, said the tweets would likely not be seen as an order to Sessions, but as “Trump venting his continued frustration with the fact that he can’t control the Russia investigation.”

“But I do think it would be a piece of evidence in the obstruction case going back to the firing of Comey because it shows Trump has this intense desire to shut down the Russia investigation,” he said.

Trump also said on Wednesday that the charges against Manafort have nothing to do with Russia collusion.

Manafort worked for pro-Russian politicians in Ukraine. While prosecutors have said they will not present evidence in this trial about possible collusion between Russia and the Trump campaign, they may dig deeper into Manafort’s connections with Russian and Ukrainian oligarchs, legal experts have said.