Scottish Labour leader Iain Gray has conceded Scots may want an independence referendum - but not at the moment.
He said it was wrong to decide on Scotland's future during a recession and under a ballot "rigged" by the SNP.
Mr Gray's comments came at the UK Labour conference, where he launched a two-pronged attack on his opponents, with Scottish Secretary Jim Murphy.
Mr Murphy told delegates in Brighton that Conservatives in Scotland were "Thatcher's grandchildren".
Mr Gray launched an attack on the minority Scottish government and its planned 2010 independence referendum, saying First Minister Alex Salmond had "no mandate, no majority and no shame".
"The SNP are not a government, they are a campaign," he told the conference, adding: "The day may well come when the people of Scotland want a referendum to settle their constitutional future once and for all, but not now in the midst of a recession and not on a question rigged and fixed by the SNP."
Taking to the stage, Mr Murphy said the only choice voters in Scotland faced come the next UK election was Labour or the Conservatives.
If the Tories won power, he said, they would make immediate and "savage" cuts to public services.
The Scottish secretary went on: "The Scottish Tory candidates are indeed Mrs Thatcher's grandchildren, because they believe in small government. They believe in the politics of sink or swim and they believe in the politics of 'you're on your own'.
"In Scotland, the Tories are hated by many because because of their past and distrusted by most because of their present. The Conservative Party still doesn't get Scotland - but Scotland gets them."