The Scottish Secretary has claimed that supporters of independence "default" to the protection of the United Kingdom on key issues of the economy.
Michael Moore said retaining UK institutions, if Scots vote to leave the union in 2014, would be an "odd notion" of independence.
His comments were made in a speech focusing on taxes and the economy at a conference organised by the Scottish Council for Development and Industry in St Andrews.
Mr Moore, a Liberal Democrat MP in the UK Government, said: "What's curious is that in these early stages of the great debate, every time reality has bitten those in favour of independence have defaulted to the protection of the United Kingdom.
"To give an example, in recent weeks we've been told that an independent Scotland would retain the pound, with the remaining UK acting as a lender of last resort, and the UK and others taking on the risk of future financial troubles in the banking sector. That's an odd notion of independence."
He said the wider debate is "real and urgent", and accused the SNP of moving "seamlessly" from the examples of Irish "deregulated Celtic Lion" to Scandinavian "social democratic haven".
Mr Moore said: "Until 2008 we were being enticed to break away from the UK and join the arc of prosperity with Iceland, Ireland and Norway. Since the financial crisis, the arc has shifted east by about 1,500 kilometres. The Scandinavian model - Denmark, Norway and Sweden - is their ideal now.
"From deregulated Celtic Lion to social democratic haven in one inelegant rhetorical flourish."
To follow the Scandinavian model would mean tax increases, not cuts like the proposed reduction in corporation tax, Mr Moore said.
He added: "In Norway, in 2009, the government took in 41.4%, in Sweden it was just under 47%, and in Denmark it stood at a fairly substantial 48.1% - more than 10 percentage points higher than the UK. That's the equivalent of more than £2,500 in tax for every man, woman and child in Scotland. Is that what the Scottish Government proposes?"