David Cameron has told Alex Salmond he will not debate Scottish independence with First Minister Alex Salmond because the Prime Minister does not himself get a vote in the 2014 referendum.
"I don't have vote. I wish I did, I know how I'd vote. I'd vote to keep our family of nations together," Cameron told the BBC's Andrew Marr show on Sunday morning. "But this is for Scots to decide."
A new SNP poll indicating a substantial proportion of the British people would like to see them go head-to-head on television.
On Sunday morning, the Prime Minister told the Sunday Times Scotland that the campaign now had to win the arguments of the "head and heart".
"I think the arguments of the head we've been winning very strongly. We now need to win some of the arguments of the heart," Cameron said.
"The UK is not something to want to belong to simply for economic reasons, but actually for emotional and historic reasons.
"In a diverse, dangerous world, the security of the United Kingdom; the ability to be part of something that could be a great success story, just as it has been in the past - we need to win those arguments."
He continued: "Obviously I'm very concerned that we win this referendum. I think the argument has been going the way of the United Kingdom, but it will not be won until every last vote is counted.
"I'll work very hard to play my part."
A Panelbase poll, commissioned by the SNP, found over three-fifths of people in Scotland and over half in the rest of the UK want a TV debate between Salmond and Cameron, compared with around a quarter on both sides of the border who do not.
A Number 10 spokeswoman said: "The Prime Minister is Prime Minister of the whole United Kingdom and of course has a role in the referendum campaign, however, he believes that the debate should be led by Scots in Scotland and that is why Alistair Darling will lead for the No campaign."
Deputy First Minister Nicola Sturgeon said: "While David Cameron is happy to pull the strings of the No campaign from 10 Downing Street, he is scared to debate with Alex Salmond face-to-face.
"As the principal signatories of the Edinburgh Agreement, the natural progression in these circumstances is a televised, head-to-head debate between Mr Cameron and Alex Salmond - a democratic position supported by a substantial majority of people north and south of the border."
A spokesman for pro-independence campaign Yes Scotland said: "A televised debate with the First Minister and Prime Minister will help Scots choose between the two futures on offer and ensure that the UK Government fully explains why it is willing to implement unwanted policies north of the border."