The management of two neighbouring community trusts is to merge after a turbulent spell in which both were temporarily without chief executives.
Southend Community Care Services trust will merge with Thameside Community Healthcare trust in April.
Insiders say this will effectively mean a take-over by Thameside managers, with chief executive Patrick Geoghegan favourite to lead the merged organisation.
Both trusts have senior managerial and clerical vacancies so redundancies are 'expected to be minimal', according to a Thameside spokesperson.
Nick Bradley, Unison eastern reg ional officer, said staff were now concerned about the impact of a takeover of learning disabilities services by three housing associations.
Last year, Southend chief executive Mike Harrison took extended leave after consultants accused him of making changes without their input.
One of the consultants involved later became the subject of police and General Medical Council inquiries. A dispute between Thameside chief executive Patrick Geoghegan and chair John Vasey resulted in them being asked to stay away from their desks last year. Mr Vasey retired last September.