A former depute leader of the SNP has announced he will vote for Alex Salmond's Alba Party at May's Holyrood election.
Jim Sillars, who won the 1988 Govan by-election in a breakthrough moment for the Nationalists, said the argument for backing the new independence movement on the list vote was "incontestable".
The Scottish political veteran fell out with Salmond in the early 1990s over differences in party strategy and became one of his most persistent critics in later years.
But Sillars - who served as a Labour MP in the 1970s before later joining the Nationalists - has now pledged to back his former political rival's new party.
In a blog post, the former SNP depute leader endorsed Alba's strategy of appealing for independence supporters to vote tactically on the list.
He said: "The arithmetic is incontestable. SNP list votes are truly wasted ones. I know, I have been at counts and seen them pile up and up, without winning a single seat.
"A list vote for Alba cannot be a wasted one, because it will count, and will return MSPs committed to independence.
"However logical that reasoning may be, it is not the only one for voting Alba.
"We are electing a parliament on May 6 for the next five years, with it facing the immediate, unprecedented, challenge of reconstructing the economy, creating and protecting jobs, achieving 'catch-up' in education for our children, especially for those in the deprived communities, and restoring the NHS to its function of delivering universal health care."
He continued: "Alba’s strategy is the same as all other parts of the independence movement, and the aim of a supermajority is a tactic towards bringing that strategic aim to fruition.
"Once in place, that supermajority will need to devise and develop other tactics to advance independence. That will mean working from within parliament in close partnership with the movement outside of Holyrood.
"That has to march hand-in-hand with the post-pandemic reconstruction, which will be the people’s most immediate priority.
He added: "If an independence party is linked to economic and social policies that matter in the day-to-day life of the people, as Alba is, then a bond is created. Trust is built.
"And it is upon that trust, born of a proven commitment to the needs and aspirations of the people, that the independence movement builds upon."
Welcoming Sillars' endorsement, Salmond said: "Jim Sillars is a serious voice in Scottish politics.
"Jim said that he would take a close look at Alba and our developing policy positions before deciding how to vote. I am therefore delighted to have his heavyweight endorsement for our campaign.”
