President Trump on Monday floated the notion of a consumer boycott of AT&T, the telecommunications firm turned media colossus, an apparent attempt to punish the company for the news coverage produced by one of its subsidiaries, CNN.

“I believe that if people stopped using or subscribing to @ATT, they would be forced to make big changes at @CNN, which is dying in the ratings anyway,” the president wrote on Twitter, shortly after touching down in Britain for a state visit. “It is so unfair with such bad, Fake News! Why wouldn’t they act. When the World watches @CNN, it gets a false picture of USA. Sad!”

Mr. Trump, who had apparently been watching CNN during his trans-Atlantic flight, complained about the channel’s coverage in an earlier tweet: “All negative & so much Fake News, very bad for U.S.” He added: “Why doesn’t owner @ATT do something?”