The economic pain of splitting the Union will be the focus of the 'No' campaign against Scottish independence, with Westminster ministers claiming the break-up would cost £140bn.
According to sources quoted in The Herald newspaper, David Cameron will visit Scotland in the coming weeks to fight to save the Union in what is being dubbed the 'Battle for Britain' campaign.
The focal point of the Coalition's campaign will be to reinforce the importance of unification and warn the Scottish people that they would face crippling national debts if the country broke away from the UK.
It is understood a Royal Commission has been mooted to investigate the economic ramifications of an independent Scotland, highlighting the issues of the armed forces, oil and gas revenues, education, welfare reform, currency and the UK's position on the global political stage without the Union.
Economists say the figure of £140bn is based on forecasts of the UK's national debt by 2014, the year Alex Salmond, the leader of the SNP, has proposed the referendum vote would take place. It is estimated the UK will be hit with a £1.4 trillion deficit of which Scotland would hold around 10%.
Alex Salmond reacted angrily yesterday to Westminster's pledge to keep the Union together and told ministers "to butt out" of Scotland's constitutional affairs. He also told Channel 4 News that he believed Scotland should not share the burden of the Royal Bank of Scotland's toxic assets, blaming the "London Treasury" for its failure. He added: "Unfortunately, they were also responsible for regulating, or at least misregulating, the financial sector as well. I'm afraid people have to take responsibility for the past mistakes they made."
In 2007, Salmond wrote a letter to the then head of RBS Sir Fred Goodwin over his ill-fated takeover of ABN Amro, saying: "It is in Scottish interests for RBS to be successful and I would like to offer any assistance my office can provide. Good luck with the bid."