“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,” the joint leader’s statement read.

“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.’”

A spokesman for Better Together, the anti-Scottish campaign organization, told RIA Novosti that they were unaware of the specifics of the surprise visit, but confirmed that the three leaders would not be appearing together in Scotland, but in individual capacities.

The move follows increased concern at Westminster that Scots voters are likely to back independence when they vote in a referendum to be held on September 18 that could end the 307-year-old union between Scotland and England. Two recent opinion polls have shown the campaigns are neck and neck, with a surge in support for the Yes side over the past month.

In a statement Alex Salmond, leader of the pro-independence Scottish National Party, responded to the announcement, “The No campaign is in complete and utter disarray, and they are making this farce up as they go along.”

“Together, David Cameron, Ed Miliband and Nick Clegg are the most distrusted Westminster politicians ever - and their collective presence in Scotland will be another massive boost for the Yes campaign,” Salmond said.