Exhausted and overworked staff at a London hospital featured on the documentary 24 Hours in A&E have been caught sleeping on the job, it was revealed yesterday.

Staff at King's College Hospital, made famous by the Channel 4 documentary, are so stretched that they have been catching 40 winks during shifts - a that trend is symptomatic of the entire NHS according to the Unite union.

A national newspaper reported having seen an internal document that warned hospital workers: "There have been a number of recent incidents where staff have been found asleep on duty, or it has been reported that staff have been asleep on duty."

Staff were caught on day as well as night shifts, as workloads for NHS staff become increasingly heavy.

A number of recent studies found more and more hours and duties are being heaped on hospital employees.

Research by the Royal College of Physicians found that 37 per cent of medical registrars found their workloads "unmanageable" and concluded that staff were at "crisis point."

A Unite survey in May last year found that 61 per cent of its 100,000 health-sector members either frequently or always worked longer than their contractual hours.

Of those 41 per cent said that these hours were all unpaid. Eighty five per cent said that workloads had increased over the year with 50 per cent saying they had increased a lot.

The report stated: "The NHS needs to recognise that staff are also patients and that burning out staff and the constant negative media attacks on them is a false economy for the taxpayer."

Unite head of health Rachael Maskell blamed staff burnout on "cuts and restructuring" within the NHS - adding that the situation is "simply unsustainable."

Ms Maskell also gave advice for staff working under such conditions.

She told the Independent: "If they are too tired to work Unite would strongly advise staff to inform their managers in order to protect patient safety, but it is symptomatic of the culture of fear that exists in many trusts if staff do not feel that they can."