Former Chancellor Alistair Darling has backed further devolution for the Scottish Parliament, as he anticipates playing "a major role" in the pro-union campaign on the independence referendum.
The Labour politician said it would be "relatively easy" to hand over income tax powers, however, echoing David Cameron's remarks during his visit to Edinburgh last week, he said the details of increased devolution should wait until after the ballot.
In an interview with a Sunday newspaper, Mr Darling said: "There's no point spending an awful lot of effort if the whole thing is redundant. If Scots vote to leave the UK then there is no point in discussing how to improve devolution."
On the powers that could be devolved to Holyrood, he added: "Income tax is easier because it is easy to identify and the Revenue knows who Scottish taxpayers are. It would be relatively easy to implement."
Mr Darling also argued for a referendum sooner than the SNP's proposed 2014 timetable, a view that was also put forward by the Prime Minister. He said: "If you want to get on to further devolution more quickly then why don't we have the referendum more quickly. Why not next year?
"I've never heard the battle cry; what do we want? Independence. When do we want it? Not yet. It is a ludicrous position to take."
Mr Darling also argued that a decision to keep the pound if a yes vote was returned would result in Scotland "going cap in hand" to the UK Treasury, due to its position as the backer behind the Bank of England.
The MP's comments come after the pro-union campaign was effectively launched by Mr Cameron in Edinburgh last week, during which he said more powers could be handed to Holyrood if voters rejected independence.
The Prime Minister did not explain what the powers could be but argued that the major decision on whether Scotland should leave the Union must be settled first.
Alex Salmond responded by warning that Scots "won't be fooled" by the offer, which Mr Cameron made for the first time. He has called for details of the proposals to be revealed before his Government's consultation finishes on May 11.