The All Under One Banner (AUOB) group, which has organised numerous political processions across Scotland, hopes to attract more than 100,000 people to its latest demonstration on Saturday, May 4.
It based that figure on the alleged turn out for a march in Edinburgh in October last year, which organisers optimistically claimed saw a six-figure attendance. Police at the time put the real number closer to 20,000.
AUOB is not officially endorsed by the SNP, but senior party figures have attended previous marches.
“We are hoping to beat Edinburgh, with over 100,000 people,” Manny Singh of AUOB told the Common Space website.
“The message is simple and it has not changed. Scotland must become an independent country, and Scotland needs to decide its own future.”
But pro-Union campaigners said such events did not reflect the views of the majority of people in Scotland.
Pro-independence marches have become an annual fixture in towns and cities across the country following the 2014 referendum, with the largest generally being held in Glasgow.
The last procession in the city saw organisers claiming a 60,000-strong turn out, although police put the number at 35,000.
Organisers believe such events act as a visual reminder of the strength of support independence enjoys.
But political opponents point out the 2017 AUOB march in Glasgow took place on the Saturday before a general election - the same vote that saw the SNP lose 21 constituencies it had won at a canter two years previously.
Pamela Nash, chief executive of Scotland in Union, said: “We hope the marchers enjoy their day out, but it’s important to understand that these kinds of events don’t reflect the views of the majority of people in Scotland.
“Most people in Scotland know we are stronger together and don’t want a divisive second independence referendum.
“SNP politicians should choose to focus on the day job of fixing our schools and hospitals rather than address this event, and start listening to the majority of people in Scotland.”