A union says plans to reduce the number of staff and vehicles delivering emergency response services will put patients at risk.

Unison officers say the East of England Ambulance Service plans will mean patients in rural areas will wait longer for a response in an emergency, and even then it will be likely to be a solo responder incapable of transporting patients to hospital.

The union says the service has held a number of vacancies empty and has already removed 110 posts and intends to remove up to a further 150 posts from the budgeted establishment, although the service has not confirmed these figures.

Although there are no ambulance stations closing as a direct result of these changes, the union says they will result in there being fewer or no ambulances capable of transporting patients at several stations across all counties within the region at certain times of the day and night.

Examples given by Unison include a 50pc reduction in double staffed ambulances in Ely and in Cromer, and North Walsham will lose one double staffed ambulance.

Gary Applin, branch secretary for Unison, said: 'The proposed scaling down of resources across all areas will put patients at risk.

'The trust's own figures show that in many areas, staffing levels will be below what is needed for many hours of the day. 'In rural areas, patients will wait for longer for any member of trust staff to attend in an emergency and even then it is likely that will be a solo responder and therefore incapable of transporting them straight to hospital.'

He added: 'These changes will also have a detrimental effect on the work life balance of our members who may be required to travel longer distances to work, and, while at work have to travel longer distances under emergency conditions on unfamiliar roads to get to people in need. Unison represents all trust employees and we urge trust management to develop alternative proposals and the Conservative/Lib Dem government to reverse the spending cuts for ambulance trusts. The public are going to suffer because of these cuts.''

The Eastern Daily Press first reported in May 2011 on the ambulance service's plans reduce its intensive care ambulance fleet size from 276 to 138 vehicles and increase its response car fleet from 145 to 232 vehicles. It could also increase its 'intermediate tier' vehicles from 21 to 105, which Unison says would look the same as traditional ambulances, but instead of being double staffed by band five or six paramedics, would instead be staffed by emergency care practitioners or assistants and therefore unable to transport the most critically ill patients.

The East of England Ambulance Service said it was not making any front line staff redundant and it was making changes to the way it works because of three challenges: an ever increasing number of 999 calls, making savings through more efficient working of more than �50m over five years and improving the quality of services to patients.

A spokeswoman for the service said: 'We are treating more people through a more in depth clinical assessment over the phone so they can be referred to the correct health service or given advice – already more than 900 patients a week are being managed by our clinicians without the need for an ambulance to be sent giving the patient a more tailored response to their needs.

'It is estimated that as this service continues to build, we will be managing up to 170,000 calls a year through this process. This is better for the patient, a more efficient way of working and frees up ambulances to respond to people in the local community who need them.'

It says this has allowed it to remove a number of existing vacant posts and it will be putting some of the remaining vacant posts back into rural areas at a cost of �400,000 as part of our promise to improve services for patients there, as well as recruiting more than 110 new emergency care assistants (ECAs) by the end of October this year and up to 10 more paramedics in Cambridgeshire.

The spokeswoman said: 'The nature of demand is changing and it is true we are, following much work with sophisticated demand prediction modelling, changing the balance of vehicles as we need less double staffed ambulances (transporting vehicles) and more rapid response vehicles (which are fully equipped and staffed by trained paramedics), and we will be allocating these to the optimum standby points to better match and meet demand in the best interests of our patients.'

However, Unison says there is no evidence that this triage system will be successful, and has called for it to be properly resourced and tested before plans are made to reduce ambulances and staff.

The ambulance service said it disputes the figures quoted by Unison, as these have yet to be decided as optimum vehicle locations and numbers have not yet been worked out and there is ongoing demand analysis work and a consultation with staff to reach the final figures.

However, Unison said it had been given the figures by the ambulance service in a consultation document, which the service refused to show to the EDP, saying it wanted to share it with staff first.