David Cameron and Ed Miliband will miss prime minister’s questions tomorrow so they can go to Scotland to try to save the Union.
The highly unusual move – announced in a joint statement with Deputy Prime Minister Nick Clegg – follows shock polling showing the future of the UK on a knife-edge.
Just yesterday Downing Street had said that Mr Cameron would not be campaigning in Scotland this week, triggering claims that he was seen as a liability to the pro-UK cause.
The U-turn came as First Minister Alex Salmond said the Better Together campaign was in a state of “total disintegration”.
The move marked another twist in the dramatic final stages of the referendum campaign, with voters going to the polls to deliver their historic verdict next Thursday.
In their statement, the three UK leaders said: “There is a lot that divides us – but there’s one thing on which we agree passionately: the United Kingdom is better together.
“That’s why all of us are agreed the right place for us to be tomorrow is in Scotland, not at prime minister’s questions in Westminster.
“We want to be listening and talking to voters about the huge choice they face. Our message to the Scottish people will be simple: ‘We want you to stay’.”
Downing Street said William Hague would stand in for Mr Cameron tomorrow.
Speaking in the garden of No 10, Mr Cameron said the parties were putting aside other differences to make clear to the people of Scotland that they could have “the best of both worlds” if they rejected independence.
The Saltire flag is expected to fly over Downing Street in a sign of commitment to the Union, a move which follows an appeal by Mr Miliband for cities, towns and villages across the UK to display the flag.
Explaining the dramatic decision to cancel his appearance in the Commons, Mr Cameron said: “I’ll do everything that I can.
“Let’s be frank, there’s a lot that the political leaders disagree about but there’s one thing that we all agree about passionately and that is that our United Kingdom is better off if we stay together.
“So tomorrow the right place to be isn’t Westminster at prime minister’s questions, it is being in Scotland, listening to people, talking to people.
“We will all have our own ways, separately, of talking about why we are better together.
“But one thing I’m sure we will all say is that it’s a matter for people in Scotland to decide, but we want you to stay.”
Asked if the highly-unusual move was a sign of panic in the Yes camp and about the security of his own position as prime minister if he oversaw the break-up of the Union, Mr Cameron said: “I really care about this issue.
“I care passionately about our United Kingdom and I want to do everything I can to put the arguments in front of the people.
“In the end it is for the Scottish people to decide but I want them to know that the rest of the United Kingdom, and I speak as prime minister, want them to stay.
“All those steps we can take, making sure people in Scotland know that they can have the best of both worlds – more powers to govern themselves but also being inside the United Kingdom.”