One of Britain's governing parties has promised Scots that, if they reject independence, Whitehall will grant them more power to set their own income tax rules.
The Conservatives, led by the current UK Prime Minister David Cameron, added that Scots would have full control over how much they are taxed on their wages, in a bid to maintain the 307-year union.
"The Scottish Parliament is a powerful institution, but it has little responsibility for the tens of billions of pounds of taxpayers' money it spends every year," said Ruth Davidson, leader of the Scottish Conservatives, in a statement.
"After 15 years of devolution, it is now time for a mature parliament that is more accountable for the cash it spends."
The Scots will be asked the straight "yes/no" question: "Should Scotland be an independent country?" on 18 September this year.
The referendum period started on 30 May.
This is the first time that the Tories have outlined new plans for Scotland's devolved government, in the event that independence was to be rejected.
Recent opinion polls show that while a majority of Scots are planning to vote against breaking away from the rest of the UK, many hope that the devolved parliament would receive more powers to govern the country the in future.