The SNP has called for the UK’s next general election to be delayed by a year to avoid a change of government during “intense” Scottish independence negotiations.
But the idea led to Labour accusing the Nationalists of supporting an extra 12 months of Tory rule.
Angus Robertson, the SNP’s Westminster leader, suggested postponing the 2015 election in case there is a Yes vote in September’s independence referendum.
He believes the complex division of the British state should be settled first, and political focus during the sensitive period not “diverted” by the UK-wide vote.
Labour seized on the comments, claiming the Moray MP backed an extended period of Conservative-led government.
Shadow Scottish secretary Margaret Curran also said that it was the 2016 Holyrood elections which should be brought forward – to end the SNP’s “irrelevant obsession” with going it alone.
The UK Government pointed out that parliament’s terms were now fixed, with the next Westminster poll scheduled for eight months after the referendum on May 7, 2015 – and that the SNP knew this when it decided the date for the independence vote.
Mr Robertson said: “I think there is a very good case for putting the UK general election back by a year.
“The reason why I say that is because of course a Yes result in Scotland will lead to a very, very intense period of negotiation between the UK Government and the Scottish Government.
“And perhaps being diverted by a general election in the middle of that process is certainly something one should be thinking about.”
Any change to the election date would require legislation which would take several months to arrange and complete.
Ms Curran dismissed the call, saying: “The SNP want another year of the Tories.
“Another year of the bedroom tax, austerity and David Cameron and if they win they’d rather negotiate with David Cameron than Ed Miliband.
“If any election should be moved it is the Scottish election brought forward so we can have a government which addresses real issues while the SNP revels in its irrelevant obsession.”
A UK Government spokesman said: “Parliament has legislated for fixed-term parliaments and the next general election will be in May 2015. The Scottish Government knew this when they chose the referendum date.”