Sussex Ambulance Service could be merged into a larger trust within three months.

Controversial plans to shake-up services by merging Sussex with Surrey and Kent are likely to take effect from July 1.

Supporters say the change will make services more efficient and save management costs but there are concerns about possible job losses and the impact on local services.

The changes tie in with a major shake-up of NHS services across the county which will also lead to Surrey and Sussex Strategic Health Authority (SHA) merging with neighbouring organisations.

The ten primary care trusts (PCTs) in the county are also expected to be merged from October 1 to create one PCT for Brighton and Hove, one for East Sussex and one for West Sussex.

Health Secretary Patricia Hewitt will receive results of a consultation held by the Surrey and Sussex SHA on the planned changes this Wednesday.

She said: "No decisions will be taken regarding the reconfiguration of SHAs, PCTs and NHS ambulance trusts before the results of the consultations have been considered and any recommendations reviewed.

"I will announce decisions as soon as possible, which may be on different timetables for the different forms and levels of organisations."

Hundreds of ambulance workers in Sussex, Kent and Surrey are being consulted on future industrial action.

Unison has called its consultation because of a continuing row about the way negotiations have been handled for a new pay and conditions deal under the Agenda for Change NHS scheme.

Concerns have included alleged interference by managers over what level of pay should be given to paramedics and ambulance technicians and planned changes to meal breaks and rest times.

The ballot asks members whether they would take industrial action should employers fail to implement the Agenda for Change under the terms of the original agreement.

They are also asked whether they would agree to the union withdrawing its cooperation with the ongoing review of possible ambulance service mergers if the Agenda for Change issue is not sorted out.

Unison has about 670 members in the Sussex ambulance service.