Nikki Haley could overtake Donald Trump in the New Hampshire primary after Chris Christie’s exit from the race gave her a boost.

Ms Haley is snapping at Mr Trump’s heels just days before the Republican 2024 contest is due to kick off in Iowa, trailing just 7 percentage points behind him.

Mr Christie, the former governor of New Jersey, held 12 per cent in that same CNN/University of New Hampshire survey before his withdrawal – a total that could push Ms Haley closer to Mr Trump.

Republicans have called Mr Christie’s exit from the race a “game changer” that could hinder Mr Trump’s ability to “run a campaign of attrition” in the run-up to Jan 15.

“There’s no question: Haley benefits,” Bill Boyd, the New Hampshire state representative, told NBC News.

“What was thought [of] as a President Trump slam dunk here in New Hampshire, is now a toss-up.”

Mr Christie was the most prominent anti-Trump candidate in the race.

Despite the potential boost, Ms Haley’s performance in a debate with Ron DeSantis, the governor of Florida, on Wednesday night called her ability to take on Mr Trump into question.

The pair exchanged barbs in their one-on-one CNN debate in Des Moines, calling each other liars and clashing over hot topics including the war in Ukraine.

But Ms Haley stumbled over her words and got bogged down in jousting with Mr DeSantis, skirting questions about Mr Trump’s character.

Although Mr DeSantis’ own performance was not widely applauded, Ms Haley seems poised to suffer the most given her need to solidify her position as Mr Trump’s main rival in the primary.

Political analysts said Mr Trump has benefited from avoiding direct engagement with his Republican rivals.

They suggested that he had delivered a surprisingly “cogent” performance at his own event which took place at the same time as the debate.

Liam Donovan, a former staff member at the National Republican Senatorial Committee, told The New York Times: “Trump’s decision not to indulge and validate the debate exercise was a shrewd move in its own right, but leaving them to tear each other apart is a nice fringe benefit.

“The little lines and digs might please their backers but it’s really tough to imagine any of this appealing to folks looking to make a decision.”

‘She’s gonna get smoked’

On Wednesday, Mr Christie was overheard predicting that Ms Haley would lose badly in an interaction caught on a studio microphone.

Minutes before he ended his own 2024 campaign, Mr Christie said that Ms Haley was “gonna get smoked”.

“She’s not up to this,” he said during a private conversation that appeared to be inadvertently broadcast online, before being deleted, ahead of his town hall in Windham, New Hampshire.

Mr Christie also said that Mr DeSantis had telephoned him “petrified”, at which point the microphone was cut off.

Mr Trump said on Truth Social, the social media platform he founded, that Mr Christie had been caught on a hot mic “making a very truthful statement” about Ms Haley.

Mr Trump’s New York civil fraud trial is back in session on Thursday for closing arguments, as the state’s attorney general seeks nearly $370 million (£303 million) in penalties from the former president for overstating his net worth to banks.

The lawsuit brought by Letitia James alleges that Mr Trump and his associates inflated the value of his assets by billions of dollars to secure better loan terms and other financial benefits for more than a decade.

Mr Trump has denied wrongdoing and said the case is a political witch hunt.