The workers at Colchester Hospital and several ESNEFT community sites, who have already taken more than 30 days of strikes against the plans, are currently in the midst of a three-week walkout.

Unison Eastern head of health Caroline Hennessy said: ‘It's incredibly disappointing to see ESNEFT make this reckless decision to sell essential cleaners, porters, caterers and other staff out of the NHS.

‘Public, political and academic opinion is all turning against outsourcing because it's worse for patients and worse for workers.

‘ESNEFT still has time to do the right thing and decide to deliver all facilities services — at Colchester, Ipswich and across its community sites — in house.'

An ESNEFT spokesperson said: ‘East Suffolk and North Essex NHS Foundation Trust Board has decided to contract all soft facilities management services to an external partner, moving to a single, consistent approach across all its sites. These services include catering, housekeeping, cleaning, portering and security.

‘Following a competitive tender exercise, including evaluation of the shortlisted bids – involving clinical and non-clinical trust staff – a preferred partner has been chosen to deliver these services. In line with public contract regulations, the trust is not able give any further information about this until Tuesday, 17 December at the earliest, once the relevant due process has been completed.'