A national day of action against outsourcing has been called on 26 February
A demonstration is scheduled in central London as part of the day.
It is backed by the RMT, PCS, IWGB and UVW unions.
In a joint statement the unions said, “For the last few years outsourced workers have been doing what many had thought to be impossible —organising and winning better rights at work.
“Now we are coming together for the first joint day of action against outsourcing.”
The protest coincides with a legal case being brought by the IWGB against the University of London which could challenge outsourcing in Britain.
Up to 100 people protested outside Goldsmiths university in south London on Thursday of last week to demand support workers be brought in-house.
The university currently has a contract with the outsourcing firm CIS and workers are demanding this ends.
It would mean improved pay and conditions.
The workers’ union, the IWGB, claims they face discriminatory practices such as being excluded from access to some catering services. The university denies this.
A previous campaign succeeded in bringing cleaners back in-house.
“We want the university to sit down with us, listen to our demands and bring us back in-house where we belong,” said Michael Bukola, Chair of the IWGB’s Security Guards and Receptionists branch.