Scotland's First Minister has been likened to North Korean dictator Kim Jong-il by the man leading the campaign to keep the country in the United Kingdom.

Former chancellor Alistair Darling, the head of the Better Together campaign, claimed remarks Alex Salmond made about support for Ukip were "something that Kim Jong-il would say".

The leader, who ruled his country for 17 years, died suddenly in 2011.

At the time of his death state television in North Korea broadcast scenes of mourning, with many people crying uncontrollably for the ''dear leader'' who in life had demanded absolute devotion from his people.

Mr Darling told the New Statesman that Mr Salmond had "said on the BBC that people voted Ukip in Scotland because English TV was being beamed in to Scotland" and added: "This was a North Korean response. This is something that Kim Jong-il would say."

Better Together said afterwards the comment was "a joke" but a spokesman for the Scottish First Minister demanded Mr Darling apologise for the "pathetic, puerile remarks".

In the interview Mr Darling spoke of a "culture of intimidation" created by the SNP and said: "When I started doing this two years ago, I didn't believe you'd be in a situation in a country like ours where people would be threatened for saying the wrong thing."

He added: "People in business are frightened to speak out. I was speaking to a senior academic who told me that he'd been warned by a senior Scottish nationalist that if he carried on speaking like this, it would be a pity for him. It's a real, real problem for us. We ought to be able to express our views without fear of the consequences...

"I haven't been threatened - they wouldn't threaten me - but if you are a member of the public and you are trashed for having your say, what do you do? You stop it. No-one wants to live in a country where this sort of thing goes on. A culture has been allowed to develop here. This is not a modern civic Scotland."

Mr Salmond's spokesman called for the Better Together leader to apologise, saying: "Alistair Darling demeans himself and his colleagues in the 'No' campaign with these pathetic, puerile remarks for which he should now apologise.

"The debate on Scotland's future is one that deserves far, far better than boorish and abusive personal insults, as do the people of Scotland.

"Mr Darling has called for a positive debate free from abuse - he should now aim to live up to that pledge, and stop trying to divert attention from the real issues."

But a Better Together spokesman said: "What an overblown reaction. Alistair was using humour to poke fun at the First Minister's disastrous TV interview where he claimed that 150,000 Scottish people voted for Ukip because BBC people in London had beamed that thought into their heads. It was a joke and it should be treated as such."

Mr Salmond himself sparked a row when he told GQ magazine that he admired ''certain aspects'' of Russian president Vladimir Putin's leadership.

The comments caused upset among the Ukrainian community in Scotland, and provoked criticism from his political rivals.