Former vice president Dick Cheney, a lifelong Republican, will vote for Kamala Harris for president, he has announced.

Liz Cheney, who herself endorsed Ms Harris on Wednesday, first announced her father’s endorsement when asked by Mark Leibovich of The Atlantic magazine during an onstage interview at The Texas Tribune Festival in Austin.

“Wow,” Mr Leibovich replied as the audience cheered.

Like his daughter, Dick Cheney has been an outspoken critic of former president Donald Trump, notably during Liz Cheney’s ill-fated re-election campaign in 2022.

Dick Cheney put out a statement on Friday confirming his endorsement, which read almost entirely as opposition to Mr Trump rather than support of Ms Harris.

“He can never be trusted with power again,” the statement said.

“As citizens, we each have a duty to put country above partisanship to defend our Constitution. That is why I will be casting my vote for Vice President Kamala Harris.”

Asked for comment, Trump spokesperson Steven Cheung said: “Who is Liz Cheney?”

The campaign confirmed Mr Cheung was being sarcastic by also pointing to a comment Liz Cheney posted online four years ago in which she called Ms Harris a “radical liberal”.

Dick Cheney, 83, has made few if any public appearances over the past year or more. He has dealt with heart issues since his 40s and underwent a heart transplant in 2012.

Dick Cheney’s statement was similar to a 2022 campaign ad for Liz Cheney as she sought a fourth term as Wyoming’s lone congressperson.

In it, he called Mr Trump a “coward” for trying to “steal the last election using lies and violence to keep himself in power after the voters had rejected him”.

The ad did little good for his daughter in a deep-red state that once held the Cheney family dear but is now thoroughly in Mr Trump’s corner.

By a more than a two to one margin, Liz Cheney lost her Republican primary to Trump-endorsed attorney Harriet Hageman.

Dick Cheney has been friends with Democrats over the years, but never supported one for president.

Both Cheneys backed Mr Trump in 2016, but after Liz Cheney criticised Trump foreign policy decisions and Mr Trump criticised the “endless wars” in Afghanistan and Iraq launched when Dick Cheney was vice president, their support waned.

If either Cheney supported Mr Trump in 2020, they were quiet about it. Meanwhile, their home state of Wyoming that year delivered Mr Trump his widest margin of victory.

By 2021, Liz Cheney’s vote to impeach Mr Trump and her investigation into him for the 2021 US Capitol riot made them irredeemable to Mr Trump — and soon most of the Republican Party.

There were exceptions. One was Cheney ally Rep Adam Kinzinger of Illinois, a Republican Trump critic who earlier this year endorsed Mr Biden and spoke in support of Ms Harris at the Democratic National Convention in August.

Several other top Republicans have come out in support of Ms Harris while some, including Sen Mitt Romney and former vice president Mike Pence, say they will not be voting for Mr Trump.

Of them only Mr Romney, who is not seeking re-election, is still in office.