Accident and Emergency departments across East England reached breaking point last night with 'black alerts' declared at five hospitals.

The huge demand on the NHS battered A&E departments with the region's biggest hospital, the Norfolk and Norwich (N&N) and King's Lynn's Queen Elizabeth Hospital both on 'black alert'.

Peterborough City Hospital and Broomfield Hospital in Chelmsford also declared black alert.

Addenbrooke's in Cambridge went a step further, declaring a critical black alert.

Black alert is a hospital's highest escalation level meaning it will look at emergency steps to free up capacity including postponing surgeries and opening day-only units overnight.

West Suffolk Hospital in Bury St Edmunds was very busy, Ipswich Hospital was busy but coping, while the James Paget in Gorleston had expected levels of demand.

A statement released by the N&N last night confirmed: 'We're on black alert and very busy.''

The crisis point was reached following huge demand on 999 ambulance services stretching back several days.

On Sunday, 53 ambulances waited at the N&N and QEH for more than the target time of 30 minutes to handover patients and get away again.

One source said it was the busiest week this financial year for the East of England Ambulance Service Trust (EEAST).

Chancellor George Osborne announced £2 billion of fresh NHS funding on Sunday, although only £1.3 billion of this is new money and the emergency measure could come too late for the region's A&E departments this winter.

With the cold weather and subsequent peak in demand it places on the NHS yet to hit, Monday's chaos is set to be repeated over the coming months.

Norman Lamb, minister of state for care and support, said: 'This reinforces this case I have made for extra resources for the NHS that we are now getting in the Autumn Statement. The system is under pressure but it has performed remarkably well over the last four years.

'The pressures just keep going. This rise in pressure is inexorable, there is no easy escape,'' said the Liberal Democrat MP for North Norfolk.

Ambulances backed up at the Norfolk and Norwich University Hospital (N&N) and Queen Elizabeth Hospital (QEH) in King's Lynn on Sunday morning in an exceptionally busy day for ambulances.

A third of all ambulances arriving at the QEH (21) waited for more than the target time of 30 minutes to handover patients and a quarter of vehicles at the N&N (32) were stuck in the same situation, according to sources.

The hospitals and East of England Ambulance Service Trust (EEAST) have made tackling ambulance handover delays one of their priorities and last week pledged they would no longer wait any more than 30 minutes in hospital car parks.

The EEAST believes it won't be able to hit emergency response targets if the delays continue.

The long waits are being put down to rocketing demand on the service with a torrent of 999 calls coming through on Sunday.

At the N&N, 26 ambulances arrived from 2am to 7am on Sunday - double the normal number.

Demand peaked at the N&N between 3am and 7am on Sunday, sources said, with 19 ambulances delayed over 30 minutes. At one point six vehicles were queued while waiting to unload their patients.

The busiest time for the QEH was from 10am to 1pm with nine ambulances delayed in those three hours.

Five crews had to wait for over 75 minutes on the chock-a-block day at the QEH.

The ambulance trust urged hospitals in a letter over two weeks ago to help it meet its target of leaving hospitals within 30 minutes of arriving.

Tactics put in place by the ambulance service and hospitals include staff known as HALOs (hospital ambulance liaison officers) who are working at the N&N, Addenbrooke's and Ipswich to minimise delays.

The trusts are also urging people to not call 999 unless it is an emergency.

Delays are also caused by a lack of beds in the hospital.

The N&N has opened an 'urgent care centre' this winter to increase its capacity at A&E by around one sixth.

It can cope with just over 300 patients a day passing through A&E.

•Do you have a health story? Email tom.bristow@archant.co.uk