After a meeting with Greenwich council managers on 17 September, Greenwich Unison expressed alarm at the council's intentions to privatise school catering and cleaning.
Unison branch secretary, Onay Kasab said: "We have been warning about this for some time. This is the first admission by the council that the services will be privatised, if the council gets its way. Effectively, the council is saying it cannot make its own in-house bid.
"If we take catering as an example, the Jamie Oliver project showed the effects of years of underinvestment and privatisation - now, in the borough that spearheaded the project, the service is to be privatised. It really is time for the council to come clean.
"We think that this is just the beginning. We strongly suspect that more services are under threat. Privatisation does not lead to better services. Just ask the elderly who rely on homecare services no longer provided by the council but instead by agencies, where time is money, home visits are time-limited and where you rarely see the same carer twice."
The union is launching an anti-privatisation campaign, beginning with a lobby of the next full council meeting on 29 October at 6pm at the Town Hall.