GMB members employed by Unite have begun a four-day strike alleging a toxic workplace culture at the trade union’s National Bargaining and Disputes Support Unit (BDSU).

The workers, members of GMB union, protested outside Unite’s London head office today, saying they voted to walk out after Unite failed to suspend managers accused of bullying and victimised those who spoke out.

But they were met by a counter-protest which accused GMB of defending the harassment of women staff and accusing that union of sexism.

GMB regional organiser Danny Adilypour said: “We have consistently seen underhand tactics used to undermine these workers’ legitimate concerns.”

A Unite spokesperson said the reasons given for the industrial action are untrue and that Unite “rightly suspended” GMB members over “serious allegations, including the alleged harassment of a [female] member of staff.”

Unite said the GMB put in a counter grievance on behalf of the men after the woman’s complaint was lodged and that its ballot of a “small number” of BDSU members was “clearly not viable.”