Billionaire Tom Steyer, who has launched a $10 million campaign calling for President Trump’s impeachment, speaks during a rally at San Francisco City Hall on Oct. 24. (Justin Sullivan/Getty Images)

A progressive mega-donor is crying foul after Fox News stopped running a TV ad calling for Congress to impeach President Trump — shortly after Trump himself responded to it.

“If Fox News is siding with Trump and trying to silence us, they must be afraid of what we have to say,” Tom Steyer said in a statement. “It shows no respect for democracy.”

Steyer, a hedge fund manager who has become one of the left’s biggest funders, launched his “Need to Impeach” campaign last month with a website, a petition and a straight-to-camera TV commercial.

On Oct. 27, for the first time, the Steyer ad ran during “Fox and Friends,” the morning show closely watched and frequently retweeted by the president. The next day, Trump tweeted his response to the “unhinged” Steyer, calling him a loser but ignoring the ad’s contents.

Four days later, according to a statement first provided to AdWeek, Fox stopped airing the ad.

“Due to the strong negative reaction to their ad by our viewers, we could not in good conscience take their money,” Jack Abernethy, Fox News co-president, told AdWeek.

According to Aleigha Cavalier, a spokeswoman for Steyer, the network did not return the money from the ad buy.

Steyer has begun a counterattack, starting with a letter from his legal counsel suggesting that the network is censoring a private citizen to curry favor with the president.

“The only plausible explanation seems to be that Fox News capitulated to political pressure from the Trump administration itself,” Steyer counsel Brad Deutsch wrote in the letter. “President Trump has threatened retaliation against broadcasters who provide him with negative coverage and Fox News appears to have answered these threats with servility.”