Further strike dates have been announced by GMB and Unite union members at hospitals in Slough and Ascot.

They will take place next Wednesday, Thursday and Friday with pickets and demonstrators expected outside the main gates at Wexham Park and Heatherwood Hospitals.

The unions oppose plans by the Frimley Health Foundation Trust to create a subsidiary company wholly owned by the NHS to run non-clinical support services. Union leaders believe the plan would effectively privatise the jobs of more than 1,000 cleaners, porters, security, catering staff and others working across the trust's three hospital sites at Frimley Park, Wexham Park and Heatherwood.

Regional GMB organiser Gary Palmer described the plan for the new company as 'only a business case singularly built around finances and not for any other benefit to either service delivery improvements and/or the patients themselves'.

A statement from the hospital trust this week said that no final decision had been taken yet about the proposed new company and expressed disappointment that the GMB and Unite unions were going ahead with the strikes.

It said: "We have agreed not to progress plans while we continue productive discussions with UNISON, who have decided not to strike while we jointly discuss alternative proposals.

"We will be focusing on keeping our services running normally for our patients, including accident and emergency, maternity, surgery and outpatient clinics, over this next period of industrial action. We achieved this during earlier action on 18 and 19 November thanks to great support from our staff and the community."

The trust insists that setting up a subsidiary company would enable a further £45m to be invested in local NHS services for patients while guaranteeing the jobs of existing staff, including no changes to their NHS pay, leave, NHS pensions and all terms of service.

Union leaders believe though that this would almost certainly change once the company was set up and that staff would lose all security.