Dr. Scott Atlas resigns from Trump administration

(CNN) Dr. Scott Atlas, a highly controversial member of the White House's coronavirus task force, has resigned from his post in the Trump administration.

A source familiar with what happened told CNN that Atlas turned in his resignation letter to President Donald Trump on Monday. As a special government employee, Atlas had a 130-day window in which he could serve and that window was technically coming to a close this week.

Atlas tweeted out a photo of his resignation letter later Monday. In the letter, he said his "advice was always focused on minimizing all the harms from both the pandemic and the structural policies themselves, especially to the working class and the poor."

"I sincerely wish the new team all the best as they guide the nation through these trying, polarized times," he wrote, apparently referring to President-elect Joe Biden's incoming coronavirus team.

The White House did not immediately respond to a request for comment.

A source close to the task force told CNN on Monday that Atlas' departure comes as welcome news, as his discredited theories will no longer have a seat at the table. A separate official said the task force remains intact following Atlas' departure.

Atlas' months-long stint in the White House was marked by controversy as he became a close adviser to Trump on the pandemic, adopting public stances on the virus much closer to the President's -- including decrying the idea that schools cannot reopen this fall as "hysteria" and pushing for the resumption of college sports.

In one extraordinary episode in October, Twitter removed a tweet from Atlas that sought to undermine the importance of face masks because it was in violation of the platform's Covid-19 Misleading Information Policy, according to a spokesman for the company.

And earlier this month, he criticized coronavirus restrictions in Michigan, urging residents in the state to "rise up" against the measures. The comments came weeks after officials thwarted an alleged domestic terrorism kidnapping plot against Democratic Gov. Gretchen Whitmer, who herself has been the subject of harsh criticism from the President and other Republicans amid the pandemic.

Atlas was not on a call Vice President Mike Pence held on Monday with state leaders, according to a list of participants. During the call, Pence and members of the task force focused on vaccine safety and distribution as Covid-19 cases skyrocket across the country, according to his office.