The Royal Free’s Accident and Emergency (A&E) department has been given a “high risk” rating a month before it is expected to be hit by winter pressures.

The hospital, in Pond Street, Hampstead, has reported its worst performance on waiting times for five years after failing to meet its target of treating 95 per cent of patients within four hours of arrival for three months running.

At its worst point, the target was missed by 1.4 per cent.

A number of factors have been blamed, including reduced bed flow, an increase in delayed transfers of care and increased A&E attendances by patients residing in Brent.

The hospital has suggested the increase in patients from Brent could relate to the closure of the Central Middlesex A&E in September this year.

It has left hospital chiefs increasingly concerned as winter approaches.

From Monday, a new “Perfect Week” measure will be implemented where the entire hospital will “work in an extraordinary way” to resolve the problem.

A Royal Free spokesman said: “We have put in place an action plan so that we reduce the number of patients who are waiting more than four hours to be seen.”