Deputy assistant to President Trump Sebastian Gorka participates in a discussion during the Conservative Political Action Conference at the Gaylord National Resort and Convention Center February 24, 2017. Alex Wong/Getty Images A letter signed by 55 House Democrats asked President Donald Trump to "immediately dismiss" Sebastian Gorka on Tuesday, adding more scrutiny to the controversial White House deputy assistant who at one point was rumored to be leaving for a new role.

"As members of the US Congress who care deeply about fighting anti-Semitism at home and abroad, we urge you to immediately dismiss senior White House counterterrorism adviser Sebastian Gorka," the letter read. "Based on recent revelations about Mr. Gorka's public support for and membership in several anti-Semitic and racist groups ... he is clearly unfit to serve in any position of responsibility in your Administration"

In March, Gorka was accused of maintaining ties to Vitézi Rend, a Nazi-allied Hungarian far-right group classified by the US State Department as "under the direction of the Nazi Government of Germany" in World War II.

He also appeared to publicly support the Hungarian Guard, a militia known for its anti-Semitic remarks that was reportedly sued and disbanded by Hungarian authorities after concluding that it threatened minorities' human rights, Forward reported.

"That is so," Gorka said in an interview after being asked if he supported the establishment of the militia.

Gorka last week was reportedly considering another role in the federal government, outside the White House, according to a senior official cited by The Washington Examiner.

White House Press Secretary Sean Spicer said on Monday there was "no belief" that Gorka was leaving the White House.

The former editor of Breitbart News has also been shunned by many members of his own field.

"Gorka does not have much of a reputation in serious academic or policymaking circles," Stephen Walt, a professor of international affairs at Harvard's Kennedy School of Government, said to Business Insider.

"He has never published any scholarship of significance and his views on Islam and US national security are extreme even by Washington standards. His only real 'qualification' was his prior association with Breitbart News, which would be a demerit in any other administration," Walt said.

Read the entire letter here »