The Right2Change movement said it aims to be the glue that binds the Left together.
The group has set out 10 principles to which it is urging political parties and General Election candidates to sign up to and endorse.
It is holding its first national conference in Dublin today.
General secretary of Mandate trade union John Douglas said that people should vote for Right2Change candidates in the General Election to put forward one strong voice.
"I think that's what Right2Change is about," he said.
"Right2Change is trying to act as the glue that holds the left together, and that's what out objective is.
"Over 25% of the population said they would vote for Independents, and we want to make sure that people, first of all, vote, and then that they would vote strategically."