Alex Salmond has accused Nicola Sturgeon of trapping Scotland in a referendum "Groundhog Day" by repeatedly promising another independence vote while "making no progress whatsoever" on getting one.
The former First Minister said his protegee and successor should "stop finding excuses" for delaying a referendum and "get on with this", arguing a vote could be held in a year if urgent preparations were made.
Comparing the situation to the Bill Murray film Groundhog Day, where the hero is forced to live the same day over and over again, he said Ms Sturgeon had placed Scotland in a referendum "time loop", but argued the situation was a "tragedy" rather than a comedy.
He warned independence supporters that "we're being led up to the top of the hill and then marched back down again" and argued she should instead start negotiations immediately with Westminster for Scotland to leave the Union.
But Ms Sturgeon rejected suggestions that she was using coronavirus as an excuse to delay, arguing that Scots had to be able to focus on the independence choice without worrying about the pandemic.
The SNP conference also overwhelmingly backed her plan to wait until the health crisis is over but stage a referendum at the "earliest" possible moment after that. She wants another vote by autumn 2023.
Delegates backed a motion by 535 votes to 10 that there should be a vote "as soon as it is safe to hold a proper, detailed, serious national debate on independence". It said the date should be determined by "data-driven criteria" about when the crisis is over.
The row broke out after Ms Sturgeon last week disclosed she had ordered her civil servants to start drawing up a "detailed" prospectus for independence. However, her programme for government for the next year did not include a referendum Bill.
A series of recent opinion polls have found a clear majority of Scots oppose staging a referendum in the next two or three years and Boris Johnson has said he will not give her the legal powers to stage one.
But Mr Salmond, who now leads the pro-independence Alba Party, said Ms Sturgeon had no strategy for overcoming the Prime Minister's opposition and "it seems very few preparations have been done to prepare the new case for independence."
Speaking ahead of his keynote speech at his party's first conference, he said: "Unfortunately Nicola has placed Scotland in a referendum time loop and it's taken six years and we're making no progress whatsoever.”
He told Times Radio: “ This is Groundhog Scotland, Groundhog referendum. We're being led up to the top of the hill and then marched back down again.
“The Alba message is, look let's get on with this and let's stop finding excuses for preparing and giving Scotland what they've voted for in five successive national elections...For goodness sake let's get on with this.”
He rejected warnings the Prime Minister would block a referendum, citing the negotiations he held with a different Tory Government ahead of the 2014 vote.
“If you can face down David Cameron and George Osborne you can certainly face down Boris Johnson and the disco king Michael Gove," he said.
“The idea that Johnson and Gove can stop a Scottish referendum when Cameron and Osborne couldn't, I think is nonsense. But it requires political determination to face down Westminster.”
He said civil servants “should have been working on the new prospectus for six years, but they need to get on with it” as the plans for an independent Scotland put forward in 2014 needed to be “refurbished”to take Brexit into account.
But Ms Sturgeon told Sky News' Trevor Phillips On Sunday show that her timetable was "about making sure that as the country faces a big, important decision about its future, it's able to focus on that properly, and that it doesn't have looming over that a Covid crisis."
She said she would want an "overall environment in the country where people are not, in their day-to-day lives, being asked to even, if not comply with legal restrictions still, limit or restrict their own day-to-day behaviour."