Scotland’s pro-union No campaign has alighted on an intriguing new plan to persuade wavering voters to reject independence: reassure them that David Cameron is about to lose the next election.

Amid signs that Labour voters are prepared to vote Yes simply as a way of ditching Mr Cameron, a senior Tory has suggested that the prime minister is unlikely to be in office for much longer anyway.

Ruth Davidson, leader of the Scottish Tories, said in a television debate on Tuesday night that “frankly it isn’t looking likely” that the Conservatives would win next year’s general election, according to opinion polls.

Ms Davidson’s comments will be reinforced on Thursday when Ed Miliband visits Scotland to reassure his party’s supporters that “the Tories are on their way out”. He will claim: “A Labour government is within our grasp.”

The recent rise in support for Scottish independence has been attributed by pollsters to a last-minute decision by Labour supporters to throw their lot in with Alex Salmond’s Yes campaign.

Mr Salmond’s new campaign tactic of arguing that only independence can save the NHS from “Tory cuts” administered from Westminster is resonating strongly in Labour’s west of Scotland heartland, where the Conservatives are toxic.

Mr Cameron said on Wednesday that Mr Salmond’s claims were “ludicrous” and that Scotland’s parliament already had control over NHS spending, but a recent poll showing the No lead shrinking to six points – 53 to 47 – suggests they are working.

Mr Miliband’s visit to Scotland will mark the start of a big push by Labour to galvanise its supporters to vote No. He will promise that the social justice promised by Mr Salmond can best be delivered by a Labour government at Westminster.

“The SNP want to tell you we can’t defeat the Tories – they are wrong,” he will say. “Change is coming in the UK. The Tories are on the way out: they are losing their MPs; they are defecting, divided and downhearted.”

Mr Miliband will promise that if Scotland votes to stay in the union, more powers over tax, social security and the work programme would in any case be devolved to the Scottish parliament.

In depth Scottish Independence Scotland will decide in a referendum to be held on September 18 2014 whether or not to end the 307-year-old union with England



Further reading

The spectre of de-industrialisation under Margaret Thatcher’s 1980s Tory government still hangs over the west of Scotland, where many of the referendum’s undecided voters are deemed to live.

Mr Cameron is expected to make only one more trip north of the border before the referendum on September 18, amid warnings from his advisers that a higher- profile presence could be counter-productive.

One cabinet minister said that officially Mr Cameron had told his team that there was no need to panic and that the No campaign was on course for victory, but that “you can see the nerves are starting to show”.