The paper’s editorial published Monday argued that Fetterman, Pennsylvania’s current lieutenant governor, has left too many question marks regarding his health after he was hospitalized for a stroke. The editorial comes after Republican candidate Dr. Mehmet Oz, a celebrity physician, has hammered Fetterman’s hesitation to agree to an in-person debate in the race that could determine control of the U.S. Senate.

Fetterman revealed on May 15 that he had been hospitalized days earlier for a stroke caused by a blood clot. The front-runner for the open Senate seat, Fetterman’s campaign said he was on his way to a full recovery and his doctors reported he hadn’t suffered any cognitive damage.

The Post editorial said Fetterman’s campaign “squandered credibility by concealing from the public for two days after his stroke that he had been hospitalized” and for waiting weeks to reveal more details about his medical record, including his 2017 cardiomyopathy diagnosis.

Additionally, the Post editorial criticized the Fetterman campaign for answering questions about his health with a doctor’s note from over 14 weeks ago stating “he should be able to campaign and serve in the U.S. Senate without a problem” with proper medication and exercise.

“That’s not good enough,” reads the editorial, noting that the paper had made similar demands from other federal candidates, including former President Donald Trump and President Joe Biden. “Mr. Fetterman is asking voters for a six-year contract without giving them enough information to make sound judgments about whether he’s up for such a demanding job.”

Oz seized on the editorial, retweeting responses to it criticizing Fetterman. A Twitter account managed by the National Republican Senatorial Committee called Fetterman a “coward.”

“He’s scared to debate because he can’t defend his radical views,” it said in a tweet.

Newsweek has reached out to the Fetterman campaign for comment.

After being subject to withering attacks by Fetterman on social media, Oz has pressed his opponent to agree to five in-person debates. After other political and media figures joined Oz’s call, Fetterman’s campaign agreed to an October debate, saying he had planned to square off with his opponent all along.

“It has simply only ever been about addressing some of the lingering issues of my stroke, the auditory processing, and we’re going to be able to work that out,” Fetterman said in a statement last week.

“We will debate sometime in the middle to end of October—as each of the past two Pennsylvania Senate races have—on a major television station to reach voters across the Commonwealth. We are still finalizing the details,” Fetterman added.

The Post’s editorial described Fetterman as “halting in his performances” since returning to campaigning, saying he “stammers, appears confused and keeps his remarks short.”

“He receives speech therapy—and we wish him a speedy, full recovery—but the lingering, unanswered questions about his health, underscored by his hesitation to debate, are unsettling,” reads the editorial.