ALEX Salmond has branded Donald Trump the “insane option” for the US presidency and suggested that, if he had a vote in the primaries, he would back Democrat challenger, the self-styled “socialist” Bernie Sanders.

The former First Minister, who this week has shunned the Holyrood election trail in favour of being in New York for America’s annual Scotland Week and to promote his book on the independence referendum The Dream Shall Never Die, appeared to revel in Mr Trump’s loss in the Wisconsin republican primary.

“We just flew in last night and we’ve managed to damage The Donald already; it’s fantastic,” the Gordon MP told LBC radio.

Having forgone his usual 30-minute weekly slot on the station because of his trip to New York, Mr Salmond nonetheless appeared on air for a few minutes to comment on the presidential race.

He told presenter Iain Dale that he had been greatly comforted by the Americans he had spoken to, who might have offered some support to Mr Trump’s political views but did not want to see him in the White House. He said most sensible people found the billionaire businessman’s “politics scary, his demagoguery offensive”.

“I was on the Canadian broadcasting corporation last night and I was saying, look, this is not really democrat/republican, it’s not really left and right; it’s sanity or insanity. There’s a lot of folk in America don’t like the insane option; so that should be quite comforting to everybody listening back home,” said Mr Salmond.

When he was asked if he would get personal satisfaction from Mr Trump failing to get to the White House, the SNP’s foreign affairs spokesman insisted: “It’s not been a personal thing with Donald…”

But he went on: “Any small contribution I can make to stopping Donald Trump from being in line for being president of the US and sitting in the Oval Office with his finger hovering over the nuclear button, then I willingly and gladly admit to signing up for that…most of the planet would be on my side on that one.”

Mr Salmond suggested, if he had a vote, he would be tempted to vote for Bernie Sanders in the primary and Hilary Clinton in the presidential race.

He added: “A lot of people regard Bernie Sanders as a grandfather but if you have the choice between the scary people like Donald Trump or Ted Cruz or your granda’ in the White House, a lot of people say let’s back granda’…You can’t believe Bernie Sanders would willingly do anything either bad or evil.”