The region's ambulance chief insisted that his organisation was on track to boost front-line staffing levels, despite experiencing a net loss of eight qualified paramedics in the last financial year.

New figures have revealed that 72 fully trained paramedics joined the East of England Ambulance Service between April 2013 and March this year. However, 80 left the under-performing NHS trust during that time, according to the results of a Freedom of Information (FoI) request.

Campaigners spoke of their disappointment at the high staff turnover at a time when the ambulance service had reached the halfway mark of its mission to recruit 400 student paramedics by March 2015.

Bosses at the ambulance service launched a recruitment drive for qualified and graduate paramedics in January. However, in the first three months of 2014, 19 qualified paramedics joined the service and 21 left the organisation.

Anthony Marsh, chief executive, said there was a national shortage of qualified paramedics. However, he hoped to recruit 50 graduate and qualified medics this year and the trust had so far offered contracts to 33. He added that the trust was addressing staff retention issues.

'We are improving morale, we are providing better support for our staff and making this a better place to work. All the actions we are putting in place will support our staff and take some of the pressure off them – more frontline staff, new ambulances, better equipment and more development opportunities for frontline staff.'

'The reason there has been a shortage of paramedics in the East of England is that the service simply has not trained or recruited enough paramedics. To a lesser or greater extent this applies to some other ambulance services elsewhere in the country. In addition, a number of student paramedics have had to wait too long to complete their training, but during 2015 all student paramedics previously on courses will have completed their training which will give the trust more than 200 paramedics,' he said.

The region's ambulance service has come under criticism from the Care Quality Commission, MPs, commissioners and patients over the last two years because of slow response times.

Between April 2011 and March 2014, 100 qualified paramedics joined the ambulance service. However, 202 left the trust, according to the response from the FoI request.

Fraer Stevenson, Unison branch secretary for the ambulance service, said staff retention remained an issue and the trust needed to find practical measures, like ending late finishing times, to support staff and raise morale.

'It has taken us years to get into this situation because of the past management decisions and because of a long-term recruitment freeze and it will take years to recover. It is worrying, but it is good it has been acknowledged. We are in discussion with the trust to make it a more attractive place to work in and address staff survey results,' she said.

Denise Burke, prospective parliamentary candidate for North Norfolk and Act on Ambulances campaigner, added: 'It is really disappointing that we are still losing more qualified paramedics than we are recruiting. It is good news about the new student paramedics, but it will be some time before they are fully qualified. We have talked in the past about it taking some time to turn around, but we seem to be taking two steps forward and one step back and there is still concern about ambulance response times.'

Have you got a story about the ambulance service? Email adam.gretton@archant.co.uk