The Radical Independence Campaign (RIC) was active during the build-up to the Scottish independence referendum in 2014.
But little has been heard from it since and it emerged on Monday that differences over "purpose, internal organisation and overall political strategy" had brought about its demise.
"The original purpose of RIC is no longer fulfilled due to these strategic and organisational differences, fragmentation of the original coalition and loss of connection with working-class communities across Scotland," a resolution passed at its AGM on Sunday stated.
"It is therefore proposed that RIC (S) as a national organisation and any remaining infrastructure supporting its function is dissolved."
The statement added; "There are important debates that should happen among like-minded people, many of whom are not present at this AGM, as we move into a new phase around Scottish independence.
"Such discussions are desirable and require substantial space and time so that trust and good working relationships can be re-established and developed.
"For the reasons above and as a result of recent experience, RIC no longer serves the purpose it was established to fulfil."
A statement posted on the body’s website says it was was disbanded due to "excessive factionalism".
But the post added: “Some local groups may still choose to operate under the RIC name."
The resolution passed on Sunday states the RIC was “one of the few organisations of the Scottish left that has made a wider national impact in the last decade”.