A packed A&E department was forced to turn away ambulances and declare a state of emergency just weeks after the controversial closure of a neighbouring emergency ward.

NHS bosses had insisted Barnet Hospital was well prepared to cope with the influx of patients following the cost-cutting closure of Chase Farm’s own A&E department on December 9.

But less than seven weeks later, Barnet Hospital was left crippled by the huge number of walk-in patients and ambulance arrivals on Friday, January 31, a letter leaked to the Times Series has now revealed.

At the height of the crisis, ambulances were left queuing outside the hospital and, by 2.30pm, 19 had been left unable to transfer their patients because of the drastic bed shortage.

Internally, a further nine patients could not be moved from their AAU ward to the emergency department, which was forced to seek help from medical departments across the region, including the Royal Free and Whittington Hospitals in central London.

The leaked letter, sent to medical departments across East and North Hertfordshire, urged GPs to avoid referring their patients for hospital treatment until as late as Tuesday to allow hospital staff to cope with the backlog.

The incident, described by one NHS spokesperson as “extremely rare”, has sparked outrage among politicians and campaigners who say they had warned for years about closing Enfield’s biggest A&E department.

Kate Wilkinson, founder of the Save Chase Farm campaign group, said: “It’s putting lives at risk. This has become a very dangerous situation where there are not sufficient front-line services to deal with the demand.

“There needs to be some serious and honest discussions with the decision makers now, who need to admit there is a lack of services.”

The trust in charge of the two hospitals replaced Chase Farm’s A&E department with a 12-hour-a-day urgent care centre in December as it centralised services at Barnet and North Middlesex.

Today it blamed the state of emergency on “winter pressures” but politicians were quick to point the finger firmly at the A&E closure.

Nick de Bois, Conservative MP for Enfield North, said: “It is yet another example of what we warned would happen as a result of putting too much pressure on Barnet and North Middlesex.

“We were told repeatedly that they would be able to cope but this shows that they clearly cannot.”

The winter pressures argument was also dismissed by Ms Wilkinson, who said the trust has not been faced with anything close to the challenges of previous years.

She said: “We have not had long spells of freezing temperatures or a superbug, as we did last year. Imagine if we had, what kind of state would we be in now?”

Tory Chipping Barnet MP Theresa Villiers, meanwhile, described the situation as "worrying".

Campaign group the North East London Council of Action organised numerous protest marches in the lead up to the downgrade of Chase Farm.

Group leader Bill Rogers described the closure as “incompetence” and said the state of emergency was “the logical result”. The group is already planning a new protest on March 8.

He said: “When you close an A&E you immediately put pressure on surrounding departments. The scenario of people waiting hours to be treated is has become increasingly common.”

A spokesman from Barnet and Chase Farm Hospitals NHS Trust said: “Barnet and Chase Farm Trust experienced high numbers of attendances and ambulance arrivals to A&E on January 31.

“As a consequence of this, and in line with the NHS England (London) policy, Barnet Hospital declared an internal emergency and received support from local hospitals and non-urgent ambulances were diverted. 

“Quality of care and safety of our patients is paramount. Consultants and senior managers were on site throughout to ensure the trust responded to this increase in activity. 

“There was a full range of services available for patients with additional staff on duty.”