Former vice-president Mike Pence on Sunday said he would answer “the call of law” and give evidence against Donald Trump if required as the rift between the pair widened.

Mr Pence could be a key witness in the latest case brought against the former president, who has pleaded not guilty to four counts relating to his attempt to overturn the result of the 2020 election.

“I have no plans to testify, but people can be confident we’ll obey the law,” Mr Pence said on CBS’ Face the Nation on Sunday. “We’ll respond to the call of the law, if it comes, and we’ll just tell the truth.”

Pointedly, on the same programme Mr Pence refused to say whether he would vote for Mr Trump, should he be the Republican presidential nominee next year.

Last week’s indictment chronicled how Mr Trump and a number of co-conspirators repeatedly lied about the results of the 2020 vote after he lost the election and pressured Mr Pence and state election officials to take action to help him cling to power.

Those efforts culminated on January 6, 2021, when Trump supporters violently stormed the Capitol in an effort to stop the certification of Joe Biden’s victory.

Mr Pence, who is running against Mr Trump for the Republican Party’s nomination in 2024, insisted he had no alternative but to defy the pressure from his former boss.

“I had no right to overturn the election,” he told CNN.

His remarks came after Mr Trump used his Truth Social channel to unleash a vitriolic attack on his one-time deputy, describing him as “delusional”.

“WOW, it’s finally happened! Liddle’ Mike Pence, a man who was about to be ousted as Governor Indiana until I came along and made him V.P., has gone to the Dark Side,” Mr Trump said.

“I never told a newly emboldened (not based on his 2% poll numbers!) Pence to put me above the Constitution, or that Mike was ‘too honest,” he added, citing the 45-page indictment brought forward by the Department of Justice.

The “contemporaneous notes” Pence took in the run up to the Jan. 6, 2021 riot, are frequently cited in the indictment.

“He’s delusional, and now he wants to show he’s a tough guy,” Mr Trump said.

Meanwhile, John Lauro, a member of Mr Trump’s defence team, welcomed the prospect of Mr Pence testifying as he toured US television networks on behalf of the former president.

“The Vice President will be our best witness,” he said on CBS’ Face the Nation as he played down the rift between the former running mates.

“Now, of course, there was a constitutional disagreement between Vice President Pence and President Trump, but the bottom line is never, never in our country’s history have those kinds of disagreements been prosecuted criminally? It’s unheard of,” Mr Lauro added.

He also confirmed the Trump defence team was seeking to have the case thrown out, arguing any actions the former president took after the 2020 election were “aspirational asks,” protected by free speech.

“This is what’s called a Swiss cheese indictment and there’s so many holes that we’re going to be identifying and mitigating a number of motions that we’re going to file on First Amendment grounds, or the fact that President Trump is immune as president from being prosecuted in this way,” Mr Lauro said.

Should the trial on the charges filed by special prosecutor Jack Smith relating to the election go ahead, Mr Trump’s team will try to move a hearing away from Washington DC to West Virginia – a state he won by nearly 40 points.

“I think West Virginia would be an excellent venue to try this case,” Mr Lauro said.

Mr Trump added he was seeking Judge Tanya Chutkan’s recusal from the case over concerns he would not receive a “fair trial”.

Rival Republican candidate Chris Christie meanwhile dismissed the calls to shift any eventual hearing away from Washington DC.

“I believe jurors can be fair. I believe in the American people. And I believe in the fact that jurors will listen fairly and impartially,” Mr Christie, a former prosecutor, told CNN.

Meanwhile, another of Mr Trump’s lawyers, Alina Habba, predicted he could face a further indictment, this time from Georgia, within weeks.

The former president was taped asking Brad Raffensperger, Georgia’s secretary of state to “find” the 11,780 votes he needed to reverse his defeat there in 2020.

Speaking on Fox News on Sunday, Ms Hubba said she expected an indictment from Fulton County District Attorney Fani Willis,

“I think that it’s been highly spoken about. I think, if you look at the barricades, the fact that she’s got her PR team doing fresh pictures for her, it’s a good indicator that Fani wants her moment, and she will — she will get on the bandwagon with the rest of the corrupt DAs and AGs that we have seen out of this country,” she said.