David Cameron has said he is ready fight for the life of the United Kingdom, as he set out his reasons why he believes Scotland should not become independent.
Speaking in Edinburgh on Thursday afternoon, the prime minister said the break-up of the UK would create "artificial barriers between" England, Scotland, Wales and Northern Ireland.
"Our Union isn’t some antique imposition. It’s living, free and adaptable. It’s admired around the world as a source of prosperity, power and security," he said.
"In an increasingly uncertain world, where risks proliferate and atomisation threatens our ability to look out for one another nothing encapsulates the principle of pooling risk, sharing resources and standing together with your neighbour better than the United Kingdom.
"We’re stronger, because together we count for more in the world, with a permanent seat on the United Nations Security Council, real clout in NATO and Europe and unique influence with allies all over the world."
He added: "I'm ready for the fight for our country's life."
Cameron was speaking ahead of a meeting with Scottish first minister Alex Salmond to discuss the terms of a referendum, due to be held in 2014.
In his speech he acknowledged that the Conservative Party was not incredibly popular in Scotland, it has only one MP north of the English border, and said he had to show a "little humility".
But he dismissed suggestions that he would be happier to see Scotland break away as it would make it easier for him to form a majority government in Westminster as the prime minister of just England.
"I'm not interested, I don't care, that's not the job I want," he said.
"I’m not here to make a case on behalf of my party," he added. "It is time to speak out, whatever the consequences, because something very special is in danger - the ties which bind us in the country we call home."
He said Scottish voters should not choose to leave to UK based on an attachment to "ancient myths, blood-soaked memories and opposition to others".
The most recent poll on Scottish independence - released on the 5th of February - suggested Scots favoured staying within the UK by a margin of 5%.