DAVID Cameron will not have to resign if he loses the battle to keep Scotland in the United Kingdom, Philip Hammond has made clear.

The Defence Secretary, when asked if, given the magnitude of what was at stake - the future of the 300-year-old Union - if the Prime Minister would be forced to tender his resignation if he failed to secure a No vote, at first stressed how he had never considered the matter.

"I genuinely have never given that question a moment's thought. This is a referendum, not a General Election."

Asked again if Mr Cameron's job was on the line, Mr Hammond said: "I don't think that's an issue at all. This is not about the Prime Minister. You could equally ask the question about the Leader of the Opposition and the leader of the Liberal Democrats. All three Westminster parties are committed to maintaining the Union."

One unnamed Minister has suggested Mr Cameron would indeed have to consider his position, noting: "It would be very difficult because he would go down in history as the Prime Minister who lost the Union."

But when a senior Downing Street source was asked about the issue of resignation, if there were a Yes vote, he replied that the matter had never been raised and what Mr Cameron was entirely focused on saving the Union.