Leaders on both sides of the independence debate have clashed over plans for a written Scottish constitution.
Deputy First Minister Nicola Sturgeon told a local authority conference it would enshrine the rights of councils.
Former UK chancellor Alistair Darling said a constitution would be "hot air" without the funds to back it up.
The pair spoke separately at the Convention of Scottish Local Authorities conference in Fife.
Ms Sturgeon has set out plans for a constitution in the event of a "Yes" vote in the 2014 independence referendum, which would include areas like free education and a ban on nuclear weapons.
She told the conference: "I can announce today we will also argue for Scotland's constitution to guarantee the status and rights of local government.
"The role of Scottish local authorities should be entrenched in a written constitution; a democratic settlement that only independence offers.
"Such constitutional protection is mainstream in developed democracies such as Germany, Denmark and Sweden."
Ms Sturgeon also criticised UK government welfare changes and its "under-occupancy charge", dubbed by critics as the "bedroom tax" - arguing that such an approach would not be taken if she had a say in an independent Scotland.
Mr Darling, who leads the pro-UK Better Together campaign, questioned the idea of a constitution, while referring to a recently leaked Scottish cabinet document which warned of "cost pressures" on public spending and volatility in oil revenue.
He said: "I've heard what has been said about a written constitution. I was a lawyer once, Nicola was a lawyer as well.
"I'm innately suspicious of written constitutions. A written constitution without the resources to back it up is hot air."
The Scottish Labour MP said of the leaked paper: "We now find out that there is within the Scottish government some understandable thinking about the problems an independent Scotland would face.
"In particular, what is shows is that it faces a very uncertain landscape where the spending pressures are great and are likely to increase and where cash is likely to be short."