David Cameron has signalled that he will resist calls to quit if Scotland votes for independence in tomorrow's referendum.
The prime minister is likely to come under pressure, including from his own MPs, if the poll results in the break-up of the United Kingdom. But speaking to reporters during a visit to a factory in Fleet, Hampshire, he said he was determined to fight on to next year's general election.
"My name is not on the ballot paper. What's on the ballot paper is 'does Scotland want to stay in the United Kingdom, or does Scotland want to separate itself from the United Kingdom?'. That's the only question that will be decided on Thursday night. The question about my future will be decided at the British general election coming soon."
With the opinion polls on a knife-edge, there is dismay among Tory MPs at the prospect of a possible Yes vote. Even if the result is in favour of remaining part of the UK, some Conservative are angry at the way the three main party leaders have promised greater devolution of powers to Scotland while continuing higher levels of public spending.
Cameron sought to play down suggestions of backbench unrest, saying that the whole party believed in "our family of nations".
"The Conservative Party and all our backbenchers want to see the United Kingdom survive and thrive," he said.
The prime minister admitted that he was feeling "nervous" ahead of the vote, but insisted that he was confident about the case for a No vote.
"Well of course everyone who cares about our United Kingdom - and I care passionately about our United Kingdom - is nervous," he said.
"But I'm confident that we've set out how Scotland can have the best of both worlds - a successful economy with a growing number of jobs ... combined with the ability of Scots if they vote No to have even more powers and even more say over how to run their own affairs in Scotland."