Former House Speaker New Gingrich, a key ally to President Trump, told "CBS This Morning" that the ongoing investigation into Russian meddling of the election, led by special counsel Robert Mueller, is a "rigged game" for its lack of pro-Trump attorneys on the case.

While Gingrich said he would not recommend that Mr. Trump should fire Mueller, he questioned the investigation's impartiality since Mueller has so far hired four Democratic attorneys.

"He apparently couldn't find a single pro-Trump attorney to hire, and I just think that's a rigged game, and I think that it's a mistake to pretend this is going to be some neutral investigation," Gingrich said.

Newsmax CEO Chris Ruddy, a friend of the president, told PBS' host Judy Woodruff on "NewsHour" that Mr. Trump was considering "perhaps terminating the special counsel."

When asked if he thought the attorneys were "anti-Trump", Gingrich responded, "Well all four gave money to the Democrats," and later laughed off a suggestion that they were the best attorneys Mueller could find.

"You're suggesting that in the entire country there are no Republican attorneys that Mueller might have hired," he added, "I don't give the benefit of the doubt to somebody who could only hire Democrats but claims we ought to trust him."

However, Gingrich said that Mr. Trump is "actually pretty confident" in the investigation and "ultimately, he's still going to be president and this stuff is all going to go away."

Gingrich's comments mark an apparent change of heart, as he previously tweeted his overwhelming support of Mueller, once calling him a "superb choice."

Robert Mueller is superb choice to be special counsel. His reputation is impeccable for honesty and integrity. Media should now calm down — Newt Gingrich (@newtgingrich) May 18, 2017

Gingrich's advice to Mueller?

"Let's just have transparency," Gingrich said, "Could we have as many pro-Trump lawyers as we have anti-Trump lawyers?"