In May, police officers were on hand to contain hundreds of

Campaigners have pleaded with Nigel Farage to stay away from Scotland after he announced plans to hold a pro-union rally a few days before the referendum.

The Ukip leader wants to open a new front in the campaign against Scottish independence, but his plan to address supporters in Glasgow next Friday, six days before the vote, has caused consternation among the established Better Together allies.

Mr Farage’s campaign appearances in Scotland have previously attracted large protests. In May last year he had to be escorted away under police protection after he was trapped in a pub in Edinburgh by an angry mob chanting, ‘Scum, scum, scum’.

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Trapped: Ukip leader Nigel Farage needed a police escort to protect him from a mob in Edinburgh following a press conference in a pub to promote his candidate for a by-election in Aberdeen

When he last visited Scotland during the European election campaign in May this year scores of policemen and vans were on hand in the capital to contain hundreds of protesters.

Pro-union campaigners are concerned that Mr Farage’s visit to Glasgow, which has become the key battleground city, will put off traditional Labour voters, who are seen as crucial to securing a No vote.

The event is also likely to overshadow a rally planned by Labour on the same day in the city, which will see leader Ed Miliband share a platform with former prime minister Gordon Brown for the first time since Mr Brown left Downing Street in 2010.

Strategists had hoped the joint event would help revive the floundering No campaign. Speculation is growing that a poll this weekend will show a significant Yes lead for the first time at a crucial time in the campaign.

Last night, Murdo Fraser, a Tory member of the Scottish Parliament, said: ‘I think it would be best if Nigel Farage stayed as far away from Scotland as possible. The arguments for staying in the UK are strong. The majority of Scots are on our side and we don’t need a distraction at this point.’

But Ukip’s Scottish chairman, Arthur Thackeray, dismissed calls for Mr Farage to stay away as ‘absolute, complete and utter nonsense’. He said: ‘We are a mainstream party and Nigel as our leader is coming up in support of a No vote.’

Earlier this week, Mr Farage described the efforts to save the 300-year-old union as ‘very lame’. Asked about his planned rally, he said: ‘I’ve no doubt I’m in for a rough