President Trump has widened his search for a new FBI director after sources told Fox News that his recent frontrunner, former Sen. Joe Lieberman, is out to the running to fill the vacancy.

Politico reported that Democrats were opposed to the idea of a former politician taking the position-- despite the fact that Lieberman was a former Democrat and later an Independent.

Lieberman is a senior counsel at a New York law firm that represented Trump for years, Reuters reported. Trump recently picked Marc Kasowitz, a lawyer at the same firm as Lieberman, to oversee his personal legal affairs.

Trump fired the former FBI head, James Comey, earlier in May. US News and World Report reported that the search for the last FBI director spanned two years.

At first it seemed like Trump was going to find a relatively quick replacement.

It was just last week when Trump told reporters in the Oval Office that he was “very close” to naming a new FBI director, and when asked point-blank if Lieberman was the leading contender, Trump replied, “Yes.”

Democratic leaders like Sen. Chuck Schumer, D-N.Y., raised questions about selecting a "career politician" like Lieberman. But Lieberman's supporters said he has extensive law enforcement experience. He was a two-term attorney general for the state of Connecticut, spanning from 1983 until his resignation in 1989 when he was elected to the U.S. Senate, serving from 1989 until 2013- first as a Democrat, then as an independent.

Meanwhile. the Senate intelligence committee announced late Friday that Comey had agreed to testify at an open hearing at an undetermined date after Memorial Day.

Comey will be asked about encounters that precipitated his firing, including a January dinner in which, Comey has told associates, Trump asked for his loyalty. In the Oval Office weeks later, Comey told associates, the president asked him to shut down an investigation into former national security adviser Michael Flynn.

The Associated Press contributed to this report