Image caption Mr Wilson said he was "forbidden" from speaking about Islam "favourably"

A UKIP election candidate has quit the party over comments made by the party's only Scottish MEP about a Scottish government minister.

Tim Wilson has decided not to stand in South Northamptonshire after David Coburn MEP compared Humza Yousaf to convicted terrorist Abu Hamza.

Mr Coburn has apologised for the remarks, saying it was a "joke".

A spokesman for UKIP said Mr Wilson had failed to emphasise local issues in his general election campaign.

UKIP leader Nigel Farage said Mr Coburn's remarks were a "joke in poor taste" but he would not be taking any action against him.

But Mr Wilson said he was disillusioned with the party over the "racist jibes" and has decided to stand down.

He told BBC Scotland he was appalled by Mr Coburn's comments about Mr Yousaf and frustrated by the inaction of the party's leadership on the issue.

He said David Coburn had produced "what I can only describe as an Islamaphobic insult, and that's simply not acceptable".

Mr Wilson added: "Of course he went on and apologised. I think, frankly, that if you are in a position of power you have to be able to control what ideas emerge from your head and how they get to your mouth and, in fact, you shouldn't have those ideas in the first place.

"But the real issue is that when Mr Farage was asked what he thought about this he dismissed this as a joke.

Image copyright PA Image caption UKIP MEP David Coburn said his comments were "inappropriate"

"I don't think this is a joke. I think this is something very serious. It may not be that this man intended to cause offence but we aren't interested in what his intentions are. We are interested in the effect what he says has on other people and the effect is catastrophic, it's appalling and I've resigned."

In his resignation letter, Mr Wilson said he had been "systematically gagged by the party whip" and forbidden to speak about Islam favourably.

A spokesman for UKIP said Mr Wilson had failed to put more emphasis on local issues in his campaign.

'Out of his depth'

He said: "Whilst we had initially been optimistic about Tim Wilson's abilities as a candidate, it became obvious in recent weeks that he was out of his depth in representing our party in the way we would expect.

"Mr Wilson had clearly misunderstood the expectations that UKIP place on all of its candidates. Principal amongst those is focusing on issues that are relevant to local voters. UKIP put huge emphasis on local issues and Mr Wilson was unwilling to follow UKIP guidelines in this respect."

Last week MSPs at the Scottish Parliament unanimously condemned the remarks made by Mr Coburn during a newspaper interview.

MSPs were debating a motion celebrating Scotland's diverse communities.

The president of the European Parliament, Martin Schulz, condemned the remarks, saying they were "not worthy of any elected member".

But a spokesman for the president said he could not act on remarks made outside parliament.

The move comes just days after another candidate, Jonathan Stanley, quit in protest at the "racist filth" in UKIP. Mr Stanley, who was due to stand in the Cumbrian seat of Westmorland and Lonsdale, was the party's former head of policy in Scotland.