Former New York City mayor Rudy Giuliani in critical condition in hospital

Rudy Giuliani, the former New York City Mayor and a long-time champion of President Donald Trump, is in a "stable but critical condition" in hospital, his spokesman has said.

"Mayor Giuliani is a fighter who has faced every challenge in his life with unwavering strength, and he's fighting with that same level of strength as we speak," Ted Goodman said in a social media post.

Shortly afterwards, Trump described Giuliani as "the Best Mayor in the History of New York City, BY FAR" on Truth Social and praised his efforts in contesting the 2020 election, won by Democrat Joe Biden.

No further details on his illness have been released. Giuliani, who is 81, was injured in a car accident late last year.

Goodman added at the end of his post: "We do ask that you join us in prayer for America's Mayor Rudy Giuliani."

Giuliani earned that nickname after leading New York City through the aftermath of the 9/11 attacks.

In recognition of his leadership, he was awarded an honorary knighthood (KBE) by Queen Elizabeth in 2002.

His second term in office ended at the end of 2001 and he later made an unsuccessful presidential run for the Republican Party.

He was key backer of his fellow New Yorker's 2016 White House run, most publicly at the Republican National Convention. He later became Trump's personal lawyer.

After the 2020 presidential election, Giuliani and other advisers travelled across the country making false claims about the results, accusing Trump's opponent Biden of attempting to steal the election.

Later, a jury forced him to pay two election workers whom he had accused of ballot fraud $148m (£108m) for defamation.

In his social media post expressing concern for Giuliani's health, Trump repeated his false claims about Democrats stealing the 2020 election.

"They cheated on the Elections, fabricated hundreds of stories, did anything possible to destroy our Nation, and now, look at Rudy. So sad!" he said.

Last September, Giuliani was a passenger in a Ford Bronco when it was struck from behind in the US state of New Hampshire.

He suffered a fractured thoracic vertebrae, multiple lacerations and contusions, and injuries to his left arm and lower leg, his security guard said at the time.