The challenges facing the region's under-fire ambulance service have been laid bare by a new report which reveals that the organisation will need more than 400 extra front-line staff over the next four years to meet demand.

The East of England Ambulance Service has been criticised by MPs across Norfolk and Suffolk this year for slow responses and has been ordered to improve by the health regulator, the Care Quality Commission.

The results of the NHS trust's clinical capacity review, carried out by a specialist emergency services consultancy, commissioned by the ambulance service, says that the organisation had a 'significant resource requirement' for 2014/15 to meet national targets and commissioner standards.

Board members of the ambulance trust, which is trying to recruit more paramedics, will set out their response to the review at a public meeting in Ipswich tomorrow.

However, a draft copy of the report, seen by the EDP, reveals that the organisation will need to put at least 23 extra double staffed ambulances (DSA) on the region's roads in 2014/15, 15 of which have been recommended to be located in Norfolk and Suffolk.

The review also recommends:

• The ambulance service needs 310 extra staff in 2014/15, 55 in 2015/16, and another 55 in 2016/17.

• The trust needs 38 more A&E ambulances in 2014/15 and six more RRVs.

• The review suggests that 64 extra front-line ambulance staff are brought in to North Norfolk, 48 in South Norfolk and four extra staff in Great Yarmouth and Waveney. No increase in DSA staffing is recommended in Norwich and West Norfolk.

• An additional 1,168 Rapid Response Vehicle (RRV) hours in North Norfolk to improve responses and an extra 140 RRV hours in West Norfolk.

The clinical capacity report says that North Norfolk is the worst performing area in the East of England for ambulance responses to patients suffering suspected strokes and cardiac arrests.

Norman Lamb, health minister and MP for North Norfolk, welcomed the recommendations, but called on the trust to act on the review.

'They have made promises they did not keep in the past. They said 15 extra ambulances were being brought into the system earlier this year and North Norfolk was getting an extra 24/7 ambulance, which would be initially staffed on overtime. However, it has been taken away after ten shifts. It is not good and undermines people's trust in the ambulance service.'

'It reinforces the impetus to get the chief executive position sorted out and I am putting pressure on nationally to get that resolved. We need leadership to drive change. They need to strip out layers of management to invest in the front-line and they need to get on with that,' he said.

Under projections in the new review, the trust will still not respond to 75pc of the most urgent calls within eight minutes in North Norfolk, South Norfolk, West Norfolk, and West Suffolk in 2014/15.

Mr Lamb added that he was pressing for changes to be made to ambulance performance targets.

'The gap between what they have provided in rural areas is vast. Having one target for the whole of the region distorts behaviour and NHS England is looking at ambulance targets and there is a strong case to change them to make them more local specific,' he added.

The clinical capacity review says that 70pc of RRV response call outs are not automatically backed-up by an ambulance response.

Andrew Morgan, interim chief executive, pledged to hire 350 more front-line staff earlier this year of which 231 would be paramedics and specialist paramedics by the end of this financial year.

However, whilst the trust hired 44 qualified paramedics and three specialist paramedics in the first nine months of this year, figures earlier this month revealed that 40 paramedics left the NHS trust between January and September.