Cameron says Independence would be a ‘painful divorce’

British prime minister David Cameron used his last visit to Scotland before the historic independence referendum this week to implore Scots to remain part of the United Kingdom, warning today that a breakaway vote would be irreversible.

With opinion polls suggesting the referendum remains too close to call, Mr Cameron pleaded with voters not to use the referendum as a protest vote.

"There's no going back from this. No re-run. If Scotland votes 'yes' the UK will split and we will go our separate ways forever," he told an audience packed with Conservative party supporters in Aberdeen, the centre of Scotland's oil industry.

“Don’t think: I’m frustrated with politics right now, so I’ll walk out the door. If you don’t like me I won’t be here forever. If you don’t like this government it won’t last forever. But if you leave the UK that will be forever.”

Mr Cameron’s trip was a last-ditch effort to try to persuade Scotland’s many undecided voters to reject independence. Up to 500,000 people out of more than 4 million registered voters are estimated to be unsure how they will vote.

Campaigning in Scotland is fraught with difficulty for Mr Cameron, whose party is unpopular with Scots who have traditionally voted for the left-leaning opposition Labour party and harbour bitter memories of former Conservative prime minister Margaret Thatcher's 1979-1990 stint in power.

Mr Cameron's Conservatives have only one of 59 British parliamentary seats in Scotland, and the pro-independence Scottish National Party (SNP) has elbowed Labour aside in recent years to emerge as the dominant political force.

Mr Cameron, his voice at times faltering with emotion, spoke after a video was shown extolling British achievements and some of the most prominent figures of British history from Winston Churchill to Alexander Fleming, a Scot who discovered penicillin.

“Independence would not be a trial separation. It would be a painful divorce,” he said, standing in front of a giant Union Jack flag and a poster saying “Lets stick together”.

“Head and heart and soul, we want you to stay.”

Mr Cameron has conceded his public image as a privileged Englishman with aristocratic roots does not make him the best person to advocate against Scottish independence.

Scottish nationalists criticised him for staying away in the early months leading up to the vote as complacent, and now that he is showing his face, they portray him as a condescending Englishman in no position to advise Scots on how to vote.

Details of his visits north of the English border are not revealed until the last minute for security reasons and critics say his advisers try to minimise his contact with the public to avoid nationalist heckling. The visit was expected to last only hours.

Agencies