With opinion polls narrowing ahead of the September 18 referendum and the UK prime minister – an upper middle-class Englishman – often perceived as a handicap to the No campaign, there has been speculation that some people might vote yes to precipitate Mr Cameron’s demise.
But Mr Cameron on Thursday said that overseeing the break-up of the 307-year-old union would not be a resigning matter, even though “it would break my heart if Scotland leaves the United Kingdom”.
“I think it’s very important to say no to that emphatically,” he told the BBC. “What’s at stake here is not this prime minister or that prime minister, or this party leader or that party leader. What’s at stake is the future of Scotland.”
“It’s very important for the people of Scotland to understand that this is about the future of Scotland.”
Scottish Conservatives are not ignoring Mr Cameron’s fate, however; indeed they have started using it to try and stop people voting yes in the referendum. Ruth Davidson, the head of the Scottish Tories, said in a television debate on Tuesday that “frankly it isn’t looking likely” that the party would win the next election.
Ed Miliband is likely to use a similar tactic when he visits Scotland on Thursday; he is expected to tell supporters that a Labour government is “within our grasp”.
Some analysts are attributing the recent rise in support for independence – the latest YouGov poll said the Yes campaign had closed the gap to six percentage points – to Labour supporters leaving the No fold.
Mr Cameron’s determination to stay in office whatever the referendum result first became an issue in May after reports emerged that some Scottish voters might use the ballot to punish the Conservatives, who are unpopular in much of Scotland.
Separately, Canadian media are reporting that Stephen Harper, the country’s prime minister, said that the referendum debate is, in some respects, hard for Canadians to understand.
“The idea of separating English people from Scottish people in Canada is almost inconceivable. So we have trouble relating to it on that level,” he reportedly said.
The people of Quebec in Canada have twice held independence referendums and rejected separation on both occasions.