A Pennsylvania radio host has quit after his boss told him not to criticize President Trump on the air.

Bruce Bond told Pennlive.com that he was unwilling to comply with WTPA-FM’s general manager, Tim Michaels, to lay off the president.

“I certainly didn’t want to leave,” Bond said. “Being in that studio, it was perfect. And I’m very sad that that couldn’t continue.”

The outspoken host shared an image on Facebook of a letter from Michaels, who wrote: “This is to serve as notice that it is not permissible on WTPA airwaves to talk disrectfully (sic) of the President. I have received backlash in the form of emails, phone calls and such.”

The letter says listeners have threatened boycotts of sponsors and social media campaigns against the station. The rules left him unable to be honest with his fans and listeners, he said.

“I’m sorry that there is this really ugly political environment in this country with the current President. Unfortunately, Central PA can’t handle someone as liberal & brutally honest as I can be quite often,” he wrote.

Bond said he had been warned about the matter as recently as two months ago.

“But I can’t be walking on eggshells when and if the subject of Trump comes up. I’m certainly not going to be positive,” he told Pennlive.com.

Michaels said the station accepted Bond’s resignation and wishes him well.

“That’s basically my comment on Bruce,” he said.