Tories are trying to “bully” Scotland into voting against independence by ruling out a formal currency union, Deputy First Minister Nicola Sturgeon claimed yesterday.

Ms Sturgeon said reports that Chancellor George Osborne would reject any deal allowing an independent Scotland to keep the pound were a scare tactic before the referendum.

Mr Osborne has already said it is “unlikely” that the rest of Britain would agree to a currency union.

The Chancellor is expected to use a speech in Edinburgh today to argue that “the pound is one of the oldest and most successful currencies in the world.

“I hope passionately that the people of Scotland — who make such an important contribution to life on these islands — choose to stay within our family of nations here in the United Kingdom.”

Ms Sturgeon hit back at claims that Mr Osborne, his Labour shadow Ed Balls and Liberal Democrat Treasury Minister Danny Alexander are all set to rule out a currency union with an independent Scotland.

“People won’t take kindly on the Westminster Establishment ganging up to bully Scotland in the decision we’re being asked to take on the referendum,” she told the BBC.

Ms Sturgeon said that ruling out a deal on currency would be “an absurd position for any Westminster government to be in,” adding this would “cost their own businesses hundreds of millions in transaction costs, it would blow a massive hole in their balance of payments, it would leave them having to pick up the entirety of UK debt.”

The Scottish government has set out plans to retain the pound if people vote for independence, creating a ‘‘sterling zone’’ with the rest of Britain.

Right-wing think tank the Adam Smith Institute research director Sam Bowman said an independent Scotland wouldn’t need Westminster’s “permission” to use the pound, pointing to countries in south America using the US dollar.

Federal Reserve of Atlanta research suggests they have “far more prudent and stable financial systems than if they were part of a formal currency union,” he said.