Updated

President Donald Trump slammed back at Sen. Jeff Flake in a tweet Sunday night, calling him “unelectable” and referring to his political career as “toast” days after the Republican senator was caught criticizing the president.

“Sen. Jeff Flake(y), who is unelectable in the Great State of Arizona (quit race, anemic polls) was caught (purposely) on “mike” saying bad things about your favorite President. He’ll be a NO on tax cuts because his political career anyway is “toast,” the president tweeted.

The tweet comes in response to comments by Flake Saturday night, in which he was caught telling a Republican mayor that “if we become the party of Roy Moore and Donald Trump, we are toast.”

Flake later said that his comments weren’t news, because “I’ve been saying this to anyone who will listen.”

While Trump appeared to write off Flake’s vote on the Republican tax bill, the Arizona senator's communications director tweeted that Flake "is still reviewing the #TaxReform bill on its merits. How he votes on it will have nothing to do with the president."

Flake has been an outspoken critic of Trump’s. During a speech on the Senate floor last month in which he announced he wouldn’t seek re-election, the senator called out Trump for his behavior as president, which he called “reckless, outrageous, and undignified.”

White House press secretary Sarah Sanders said the remarks were “not befitting of the Senate floor.”

The Associated Press contributed to this report.