Parties pledge powers to Scottish Parliament if Scots vote ‘no’

More powers over tax and social security will be granted to the Scottish Parliament if voters reject independence, David Cameron, Ed Miliband and Nick Clegg will announce just hours before the first televised debate on the referendum.

In a joint declaration, the party leaders will back the "strengthening" of the Scottish Parliament, devolving greater powers from Westminster if the Union is maintained after the 18 September vote. A spokeswoman for Scottish First Minister Alex Salmond said the vow was a "rehash" of old promises.

The declaration comes hours before Scottish National Party leader and Yes campaigner Alex Salmond takes on Alistair Darling, the chairman of pro-UK Better Together campaign and former Labour Chancellor, in the first live televised referendum debate.

Among the vows made in the declaration are offers of greater "fiscal responsibility and social security." It states an aim of increasing Holyrood’s powers "as swiftly as possible" after next year's general election.

“We support a strong Scottish Parliament in a strong United Kingdom and we support the further strengthening of the parliament's powers," reads the declaration.

The Scottish Labour Party, the Scottish Conservative and Unionist Party and the Scottish Liberal Democrats have each produced their own visions of the new powers which they feel the Scottish Parliament needs.

"We shall put those visions before the Scottish people at the next general election and all three parties guarantee to start delivering more powers for the Scottish Parliament as swiftly as possible in 2015. This commitment will deliver a stronger Scottish Parliament in a stronger United Kingdom."

However, a spokeswoman for First Minister Alex Salmond said "no one in Scotland will be fooled by this Westminster-led rehash of vague promises and unspecified more powers in the event of a 'No' vote – the Tories have tried that before."

"David Cameron fought tooth and nail to keep a more powers option off the ballot paper, so how can anyone take him seriously now?"

In the two-hour debate on STV, held at the Royal Conservatoire of Scotland in Glasgow before a 350-strong audience, Salmond will put the case for Scottish independence while Darling will argue for the UK to stay together. Salmond had wanted to debate with Prime Minister David Cameron, but Downing Street declined. Nevertheless, one million Scots are expected to tune into the program.

Voters will go to the polls on 18 September this year where they will be asked a ‘yes/no’ question: "Should Scotland be an independent country?"

The Yes camp knows Salmond needs to score a victory in the debate to help trigger a surge of support for independence. A recent Survation poll showed the Yes vote is tailing on 40 percent, while the No Vote is ahead on 46 percent, with the remainder undecided. When undecided voters are removed, the poll put support for staying in the UK at 53 percent, with 47 percent backing the breakup of the Union.