The Radical Independence Conference plans to meet in Glasgow Sunday, The Independent reported. The coalition includes the Scottish Greens, Scottish Socialists, some trade union militants and environmental, anti-nuclear and anti-monarchy campaigners.
"We are against austerity, we want a modern republic, one not tied to the monarchy, we oppose discrimination, Trident and nuclear weapons," said Jonathan Safi, one of the coalition's organizers. "We think these are very appealing ideas and could contribute towards strengthening the vote for an independent Scotland."
First Minister Alex Salmond, the head of the Scottish National Party, has said he would like Queen Elizabeth II to remain the head of state in an independent Scotland, and has said the country would join NATO.
While Salmond fears the leftist group will split the nationalist movement, members of the coalition suggest their version of independence will appeal to more Scots voters.
"There is a growing group of people who are not content with the SNP's version, with the SNP's policy agenda that they are attaching to the independence cause," said Patrick Harvie, a leader of the Green Party. "These are people who want to get a different message across so it's not just about the Greens, it is about a wider group. I think that over the next few years, you'll see that grouping grow."
Notable deaths of 2014 [PHOTOS]
Yemeni prime minister resigns amid fighting