‘IT was nothing personal.” That, in a nutshell, was Alistair Carmichael’s defence in court number one in Parliament House yesterday.

The Orkney and Shetland MP is trying to persuade Lady Paton and Lord Matthews to dismiss the election petition that four of his constituents have brought against him under the Representation of the People Act 1983.

They’re relying on section 106 – which makes it an illegal practice to make false statements about a candidate’s “personal character and conduct” for the purposes of winning election. If the petitioners prevailed, not only would Scotland’s last Liberal Democrat lose his seat, but Carmichael would be barred from elective office for three years. If the procurator-fiscal decided to institute proceedings, there would also be a risk of prosecution and a hefty fine. The personal consequences couldn’t be starker.

Contrary to popular misconception, the legal case has nothing to do with whether Nicola Sturgeon was a candidate, or the accuracy of the leaked ambassadorial memo. It all comes down to Carmichael’s own “personal character and conduct”. Before the election, he told Channel 4 News he hadn’t the foggiest how the French memo found its way into the pages of The Telegraph. He lied. He knew he lied. He confessed only when his singularly unsophisticated political gambit was rumbled. Francis Urquhart he ain’t.

But more than that, by lying to the media about his involvement, Carmichael deprived the people of Orkney and Shetland of an open, honest election campaign. He deprived them of the opportunity to pass judgment upon him and his deeds. Perhaps they would have returned him to parliament in any case. We’ll never know. He chose to brazen it out.

Yesterday Carmichael’s QC, Roddy Dunlop, made a lucid and careful argument in his defence. But as a lawyer, sometimes you come across a case – a point of law – which makes the ordinary punter blink with outraged disbelief. Listening to Carmichael’s defence is one of these occasions when sensible folk everywhere cry “let’s kill all the lawyers”. Politically, it is toxic.

The former Secretary of State for Scotland is relying on a well-established distinction in electoral law. “Yes”, he says, “I lied through my teeth on the airwaves and in print, but it was only a political lie, an official lie, not a lie about my ‘personal character or conduct’. So it isn’t caught by the legislation. My election should stand.” As Dunlop told the court yesterday, “from the beginning to the end, this matter was political”.

Carmichael’s QC invited the court to consider what might happen if the petitioners prevailed. It was, he said, a slippery slope. During an election campaign, every candidate would be “effectively strapped to a lie detector and administered a truth serum”. “Would that be such a bad thing?” Lord Matthews quipped. Carmichael’s legal answer is affirmative: the courts should butt out. His fibbing is between him and his electorate – perhaps some time in 2020. Nothing to see here. It was only his political self which lied. His personal self remains unblemished by it.

There are important arguments to be had about how the Act is interpreted. We don’t want unelected judges turfing elected politicians out of office too lightly. But like the cackhanded escapade which brought him to this pass, Carmichael’s legal defence is shabby, self-serving and unprincipled.