The Scottish government is accusing Westminister of bullying tactics after it emerged that the Chancellor George Osborne will rule out a formal currency union with an independent Scotland.
His position will also be backed by Labour shadow chancellor Ed Balls and Liberal Democrat Chief Secretary to the Treasury, Danny Alexander.
The Scottish government wants to keep the pound in a currency union if there is a "Yes" vote in the referendum on 18 September.
SNP ministers said the Westminster parties were bullying Scotland.
The BBC reports Mr Osborne will set out his detailed position this week, with Mr Balls and Mr Alexander expected to follow in the days to come.
In an answer to questions at a Downing Street on Tuesday, Prime Minister David Cameron, said: ''I think it would be very difficult to justify a currency union post-independence."