A movement founded by the late Bob Crow, who led the RMT union for a decade, is fielding 560 candidates in this month’s local council elections.

The Trade Unionist and Socialist Coalition was Bob Crow’s attempt to lay the foundation for a new political party left of Labour, and still has the official backing of the RMT despite his recent death. Its chairman is Dave Nellist, a former Labour MP who was expelled in 1991 as a member of the proscribed Militant Tendency.

The TUSC backed the recent strike on the London Tube, and the five-hour strike this month by the Fire Brigades Union. Since it was formed in 2010, it claims to have run hundreds of candidates in local elections and to have received 100,000 votes. It has won a small number of council seats.

Download the new Independent Premium app Sharing the full story, not just the headlines

It is unlikely to win more than a handful this month, and is too small to represent a threat to Labour. That could change if Labour loses next year’s general election – in which event, Len McCluskey, head of the massive Unite union, has hinted it might break links with Labour.