WASHINGTON, US: Republican former vice president Dick Cheney said Friday he will vote for Democratic presidential candidate Kamala Harris over Republican former president Donald Trump in the Nov 5 US elections, following a similar statement made by his daughter Liz Cheney this week.
Mr Trump and Ms Harris are locked in a tight race for the Nov 5 vote and face off in a debate next week.
Some Republicans upset with Mr Trump's control over their party and his actions have recently thrown support behind Ms Harris, including dozens of former staffers of former presidents George H W Bush and George W Bush.
Mr Cheney served as VP under GOP president George W Bush from 2001–09. He has faced criticism over the years from human rights groups as he played a large role in planning the US wars in Afghanistan and Iraq.
He said on Friday that "in our nation's 248-year history, there has never been an individual who is a greater threat to our republic than Donald Trump".
He added: "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."
Mr Trump called the Cheneys "irrelevant RINO" in a social media post Friday, using a term he applies to Republicans not loyal to him, which stands for "Republicans in Name Only".
Meanwhile, more than 90 company executives, including the chief executives of Yelp and Chobani as well as the former CEOs of PepsiCo, Ford Motor Co and Yahoo!, also endorsed Ms Harris for the presidency in a letter released on Friday.
Separately, more than 100 current and retired law enforcement officials backed her, citing her experience as a prosecutor and her commitment to curb gun violence.
The executives, which include the heads of top sports and investment firms, said they were confident that the Democrat would continue to bolster the economy and preserve American democracy.
"Harris has a strong record of advancing actions to spur business investment in the United States and ensure American businesses can compete and win in the global market," they wrote.
"She will continue to advance fair and predictable policies that support the rule of law, stability, and a sound business environment, and she will strive to give every American the opportunity to pursue the American dream," they added.
Among those backing the vice president were billionaire Mark Cuban, former 21st Century Fox CEO James Murdoch and Earvin "Magic" Johnson, according to the letter obtained by Reuters and first reported by CNBC.