Alistair Carmichael has said he “enormously” regrets allowing his special adviser to leak a memo about Nicola Sturgeon allegedly wanting David Cameron to continue as Prime Minister.
The former Scottish Secretary also told judges he did not lie to a Channel 4 News reporter in a bid to protect his personal reputation.
He told the journalist that he did not know anything about the leak until another member of the press phoned him seeking a comment about the document.
Mr Carmichael said the reason why he told the untruth to the interviewer was that he wanted journalists to focus on the SNP’s alleged double standards.
He said the nationalists had claimed to voters that they were a left wing party while their strategists privately preferred the prospect of a Conservative victory to a Labour one.
Constituents have taken him to the Election Court as they believe his conduct in the light of a story published by The Daily Telegraph about the memo breached electoral laws.
Mr Carmichael allowed his special adviser, Euan Roddin, to leak a document concerning a conversation between the First Minister and the French ambassador Sylvie Bermann.
The SNP leader allegedly told the diplomat that she wanted the Tories to win this year’s general election, although Ms Sturgeon and the French Ambassador have denied this.
The constituents want judges Lady Paton and Lord Matthews to declare Mr Carmichael’s May election to the Westminster Parliament declared null and void.
Mr Carmichael’s counsel Roddy Dunlop QC asked his client: “Do you regret becoming involved in the leak?”
Mr Carmichael replied: “Enormously.”
Earlier in evidence, Mr Carmichael told the court that he sanctioned the leaking of the memo for political reasons. He said the memo benefited the Liberal Democrats and the Labour Party.
Mr Carmichael also said that he sanctioned the leak because he believed the SNP were trying to convince Scottish voters that they were left wing.
He told the court that he thought the truth of the matter was that SNP strategists would welcome the election of a Conservative government.
Mr Carmichael added: “It [the memo] chimed with what people with a sophisticated understanding of Scottish politics thought.”
Mr Carmichael told Jonathan Mitchell QC, who is acting for the constituents, that the reason why he told an untruth about his knowledge of the memo to Channel 4 News was because he was trying to control the news agenda.
He said that if he had admitted to knowing about the memo, journalists would have written about the circumstances surrounding the leak.
Mr Carmichael said: “It had nothing to do my reputation.”
He added: “I was trying to ensure that the coverage focused on the substance of the leak; that the SNP stood to benefit from the election of a Conservative government.”
The court has heard that following the publication of the story, senior civil servants at the Cabinet Office launched an investigation into how the memo was leaked.
Mr Carmichael did not fully tell the truth about the leak to the inquiry until five days after the general election. On Monday afternoon, he said he was “less than fully truthful” with the investigation in its initial stages.
Mr Carmichael was told by Mr Mitchell that his response during the initial stages of the probe was “calculated and intended to mislead.”
He replied to that comment: “Yes, truthfully, I would have to say that.”
At the end of his evidence on Tuesday, Mr Dunlop asked his client whether he had been truthful in his account in what happened with regard to the leak.
Mr Carmichael, who was a depute procurator fiscal before becoming a Lib Dem activist, said he had been truthful.
He added: “I have seen what happened to Tommy Sheridan.”
The constituents who brought the case to court – Timothy Morrison, Phemie Matheson, Fiona Grahame and Carolyn Welling, all of Orkney – believe Mr Carmichael breached electoral law.
The quartet were aided by crowd funding.
They maintain that Mr Carmichael’s statement to Channel 4 News on when he first became aware of the leak broke the Representation of the Peoples Act.
The legislation states that a person will be guilty of an illegal practice if before or during an election, for the purpose of affecting the return of a candidate, they make or publish a false statement of fact over a candidate’s personal character or behaviour.
Mr Carmichael denies any wrongdoing.
The hearing continues.