United States President Donald Trump on Wednesday fired Attorney General Jeff Sessions and replaced him with a Republican Party loyalist who will now oversee the remainder of the investigation into the alleged Russian meddling in 2016 presidential elections, AP reported. Sessions, in an undated letter to Trump released on Wednesday, said he was quitting at the request of the president.

Trump has criticised the attorney general for over a year for recusing himself from the Russia investigation after reports on his undisclosed meetings with Russian officials surfaced. The investigation is led by Special Counsel Robert Mueller. Matthew Whitaker, who will take over as the acting attorney general, has been critical of the Mueller team and had once argued that Mueller’s probe “was going too far”, Reuters reported. Whitaker was previously Sessions’ chief of staff.

On Twitter, Trump announced Sessions resignation and immediately named his interim replacement, Whitaker. “We thank Attorney General Jeff Sessions for his service, and wish him well! A permanent replacement will be nominated at a later date,” he added.

Meanwhile, Congressional Democrats called on Whitaker to recuse himself from the Russia investigation. Deputy Attorney General Rod Rosenstein, who appointed Mueller, has so far been monitoring the probe.

“Given his previous comments advocating defunding and imposing limitations on the Mueller investigation, Whitaker should recuse himself from its oversight for the duration of his time as acting attorney general,” Senate Democratic leader Chuck Schumer said in a statement, according to Reuters.

Mueller is investigating whether Trump’s election campaign colluded with Moscow. The special counsel has brought charges against Trump’s former campaign chairman and several others, along with 25 Russians. Mueller was reportedly expected to come up with new indictments in the coming weeks.