US state challenges legality of Trump’s appointment of Matthew Whitaker, saying the pick breaks federal law.

The state of Maryland launched a court challenge on Tuesday to the legality of President Donald Trump‘s appointment of Matthew Whitaker as acting US attorney general, saying the president overstepped his constitutional authority and broke federal law.

Trump installed Whitaker as acting attorney general last week after ordering Jeff Sessions to resign from the post. Trump had repeatedly criticised Sessions for recusing himself in March 2017 from the federal investigation, now headed by Special Counsel Robert Mueller, into Russia‘s role in the 2016 US election, a probe Trump has called a “witch-hunt”.

Democrats in Congress have voiced concern that Whitaker, a Trump loyalist, could undermine or even fire Mueller.

The acting attorney general has previously questioned the scope of Mueller’s investigation and spoke about the idea of reducing funding for the special counsel so the probe “grinds to almost a halt”.

“President Trump’s brazen attempt to flout the law and constitution in bypassing Deputy US Attorney General Rosenstein in favour of a partisan and unqualified staffer cannot stand,” said Maryland Attorney General Brian Frosh, referring to Rod Rosenstein, who oversaw the Russian investigation after Sessions recused himself.

Whitaker’s appointment as the top US law enforcement official gives him authority over Mueller’s investigation, which already has led to criminal charges against a series of former Trump aides and has cast a cloud over his presidency.

{articleGUID}

Trump, Frosh said in a statement, has chosen “an unqualified and unconfirmed partisan to be the nation’s chief law enforcement officer in order to protect himself rather than the rule of law”.

Maryland asked US District Judge Ellen Hollander to bar Whitaker from appearing in an official capacity as acting attorney general in existing litigation related to the Affordable Care Act healthcare law and to substitute Rosenstein in Whitaker’s place.

Maryland argued Whitaker has not been approved by the US Senate as required by law.

The city of San Francisco, also involved in separate litigation against the Trump administration, on Monday also told the Justice Department it may sue to challenge Whitaker’s appointment.

Whitaker had been Sessions’s chief of staff for a year, acting a liaison to the White House as Trump’s relations with Sessions became increasingly strained.

Before that, he was a federal prosecutor in Iowa who had lost two races for political office and then a television and radio commentator.