Yes supporters would be "naive" to think the creation of more pro-independence parties would help them win an IndyRef2, a senior figure from the 2014 referendum has said.
Dennis Canavan called for "maximum co-operation" among campaigners ahead of next year's Holyrood election.
The former chairman of the 2014 Yes campaign said that while normal politics was suspended due to the global pandemic, many people would be looking for "radical change" when lockdown restrictions were eventually lifted.
He said it was up to pro-independence campaigners to make a case for an adequately resourced NHS and improved standards of community care.
Some Yes campaigners have speculated whether a new pro-independence party may be desirable in the wake of the Alex Salmond trial, which saw the former First Minister cleared of all charges in March.
Veteran nationalist Jim Sillars claimed last month the fallout from the court case would be like a “volcanic eruption” and said something “new” and “untainted” may have to replace the SNP.
And a new pro-independence party was last week launched by disability rights activist, who said it would stand regional list candidates at the 2021 vote.
But former Scottish Labour MP Canavan told the Record the independence movement needed to be "inclusive".
"It would be naive to imagine that the creation of more pro-independence parties will necessarily translate into more pro-independence votes in a referendum," he said.
"However, for the Yes campaign to be successful, it must be inclusive, embracing people of different political parties and people who are not members of any political party.
"The SNP, as the party of government, must obviously be in the forefront of the campaign, but SNP voters alone will probably not be enough to win victory in the next referendum.
"The Yes campaign must reach out to other parties and other individuals who are committed to the cause of independence."
Canavan predicted the UK Government would likely resort to austerity measures once lockdown was eventually ended.
He added: "For understandable reasons, public campaigning has virtually stopped as a result of the pandemic but, once the current crisis is over, many people will be looking for radical change, including an adequately resourced NHS and much better standards of community care.
"In his response to the coronavirus, Boris Johnson is showing utter confusion rather than strong leadership.
"He is completely out of touch with the people of Scotland on this and on so many other issues.
"He will no doubt try to impose further austerity measures in the aftermath of the coronavirus.
"Once the pandemic is over,the challenge for the Yes campaign will be to put forward a credible alternative vision of an independent Scotland , a caring, sharing society where people are encouraged to look after each other all the time and not just during a time of crisis."
Canavan famously quit Labour ahead of the first Scottish Parliament elections in 1999 after the party refused to select him as a candidate.
He stood as an independent in Falkirk West and was returned with largest majority of any MSP.
The political veteran stood down from full-time politics in 2007 after more than three decades as an MP and MSP, but was appointed chairman of the Yes Scotland advisory board in the run-up to the 2014 referendum.
