However, he believes the person most likely to take over from Murphy, Kezia Dugdale, is a "good prospect" who will go far in politics, but "perhaps not in her present party" – adding that he would be delighted to accept her into the SNP, like so many other Scottish Labour voters.

Similarly acerbic comments are reserved for his political enemies. Sir Nicholas Macpherson, the top civil servant at UK Treasury is dismissed out of hand for a perceived role fighting independence: “[His] grasp of history is about as good as his grasp of economics … Apparently his father is a very nice guy, but it’s not all about a case of like father like son.”

He's still singularly focussed on politics, even out of work: his favourite website is UK Polling Report and occasionally visits Scottish legal blog Lallands Peat Worrier. Traditional news outlets don't get a look-in – the most mainstream outlet he mentions is The Racing Post.

As for noted pro-independence blog Wings Over Scotland, Salmond believes it sometimes "takes conspiracy theories to the end degree" and is uncomfortable at the decision of Stuart Campbell, the site’s owner, to adopt the persona of a reverend: "I’m innately suspicious of someone who calls himself a reverend who isn’t."

He also has little time for the editor of The Spectator, who mocked him for drinking pink champagne in mid-afternoon: "What’s his name, Fraser Nelson, knows nothing about football so it wouldn’t enter their heads that I was celebrating a Heart of Midlothian victory. I usually drink straight champagne of course, but pink seemed appropriate for that day."

The two pieces of unconditional praise Salmond offers during our tour are to Nelson Mandela – whom Salmond met in parliament in 1995, when he discovered that the South African president was "a big Braveheart fan" – and to his successor as SNP leader and first minister, Nicola Sturgeon, who recently impressed an international audience on The Daily Show with Jon Stewart.

“Oh, I’d have loved to do the Jon Stewart show – but Nicola did so well, and we always knew she would,” he says. “Quality is quality, and if you have quality it shows. Once, when I was on Have I Got News for You, the guys were taking the mickey out of a charity record I did when I sang 'The Rowan Tree', but the whole audience applauded. Not mimic applause, enthusiastic applause.

“Why? Because what Ian [Hislop] and Paul [Merton] don’t understand, with their backgrounds, is that audiences love a trier. They absolutely love a trier. Within the first few sentences, similarly, the American audience sensed Nicola’s huge quality.”

As Sturgeon leads the SNP through the Scottish election campaign and beyond next year, Salmond’s attention, as foreign affairs spokesman for the SNP at Westminster, will turn to the referendum on the UK’s membership of the EU.

He has proposed "a Scottish campaign" – not, he insists, an SNP campaign – that will be completely separate from David Cameron and George Osborne, whom he clearly both distrusts and dislikes. He wants the campaign to argue a “positive case” for Scotland to remain in the EU with a “non-political figure” as its leader – although it is plain to see that he also plans a central role for himself.



“There’s no way we could fight a campaign on the basis that Cameron’s going to fight it – there’s more to Europe than the microscopic world view of the prime minister,” he says. “We’ll have a campaign which says what Europe should be doing and inspires people in a positive way – that will have to be a Scottish campaign.

“Who will do the Euro campaign’s Yes broadcast? George Osborne? That would be a blow in the solar plexus for the Yes campaign in Scotland.”