A Maryland lawyer tapped to fill the No. 2 position at the U.S. Justice Department was expected to face tough questions from a Senate panel on Tuesday about how he would handle an investigation into alleged Russian meddling in the 2016 election.

Rod Rosenstein, nominated by President Donald Trump to be deputy attorney general, would handle the Russian investigation if he is confirmed by the Senate because Attorney General Jeff Sessions has recused himself from the matter.

The Senate Judiciary Committee will hold a confirmation hearing for Rosenstein, who is now U.S. Attorney for Maryland.

Democrats are pushing for the investigation to be handled instead by an outside, specially appointed prosecutor, to avoid any potential political interference.

Senator Richard Blumenthal has pledged to use “every possible tool” to block Rosenstein’s nomination unless he commits to naming a special prosecutor to conduct the inquiry.

Sessions said last week he will stay out of any "matters that deal with the Trump campaign." He recused himself after admitting he met twice with Russian Ambassador Sergei Kislyak during the presidential campaign, despite previously testifying to the Senate that he had no contact with Russian officials.

Sessions said the deputy attorney general would be responsible for the Russia-related investigations.

U.S. intelligence agencies concluded last year that Russia hacked and leaked Democratic emails during the election campaign as part of an effort to tilt the vote in Trump's favor. The Kremlin has denied the allegations.

Rosenstein has experience working for a special counsel on investigations involving the presidency. In the mid-1990s he was part of independent counsel Kenneth W. Starr's team of prosecutors who investigated Bill and Hillary Clinton.

The 26-year Justice Department veteran is seen by many current and former department officials as a politically neutral pick. Named as Maryland’s top prosecutor by President George W. Bush, Rosenstein stayed in office through the Obama administration.

“Doing an investigation into ties to Russia or the president, Rod is just going to find the facts and apply the law whether it’s an indictment or closing the case," said Bonnie Greenberg, a federal prosecutor in Maryland, who worked with Rosenstein for 11 years. "That’s the essence of Rod.”