A proposal to send student paramedics to the most serious 999 ambulance calls would put lives at risk, a union has claimed.

The region's ambulance service has confirmed it is exploring the possibility of sending less experienced crews to red calls for life-threatening emergencies.

Unions claim this could lead to patient harm or even a death by placing inexperienced staff in situations they would struggle to cope with.

Ambulance bosses have stressed that no decision has yet been made, but chief executive Robert Morton announced the review in a Christmas newsletter to staff this week.

Fraer Stevenson, Unison branch secretary said: 'Sending students to emergency calls without a qualified member of staff is a significant change to the way the trust currently responds to patients.

'We have real concerns this could place patients and staff at risk.

'This change appears to be about target chasing and not about what's right or safe for patients, or our paramedics of the future - who need to be supported through their development alongside mentorship from experienced, qualified staff.'

Former trust boss Dr Anthony Marsh had introduced strict guidelines which prevent sending unqualified staff to an emergency calls without a qualified member of staff.

Former health minister Norman Lamb has written to the trust to express his 'serious concerns' and has asked whether the trust's medical director supports the move.

He pointed out that a London coroner issued a prevention of future deaths report after students attended an emergency call where a patient died. It resulted in a change in the way that the London Ambulance Service allocate resources and the trust stopped sending students to emergency calls without a clinician.

A spokesman for the East of England Ambulance Service NHS Trust said: 'As part of our continuing drive to improve services, we are looking at how we can provide a better and faster response to those patients in the greatest need.

'One of the areas under discussion is how we deploy our staff and resources.'

The spokesman said that staff requested the review, and added: 'It is important to note at this time that nothing has been agreed or approved and no changes have been made.'

One paramedic speaking anonymously said: 'It's obviously not ideal, but if your relative was having a cardiac arrest and you had a student-only crew nearby who were able to provide effective CPR until a qualified paramedic arrived, wouldn't you want that?'