The head of NHS London has written to all the capital’s primary care trust cluster chiefs after becoming “extremely concerned” over accident and emergency performance, HSJ has learned.

Dame Ruth Carnall emailed cluster chiefs on 27 February, explaining that despite a mild winter and £30m of extra spending to improve emergency performance, several trusts are “almost certain to fail” to hit target for quarter four of 2011-12.

In the letter, seen by HSJ, she wrote: “I am extremely concerned at the level of A&E performance currently being delivered across London. Compared with the last two winters, we have not seen a recovery in performance following the dip in December and early January.”

She said the previous week’s overall performance, which saw 94.1 per cent of patients being admitted or discharged within four hours, was the worst yet in 2011-12.

Dame Ruth said: “Ambulance handover delays are also very concerning as a key indicator of patient care.”

Clusters were reminded that the £30m in “access initiative funding” should have helped trusts improve emergency performance.

Yet of the 19 trusts that received a share, only six hit their targets for January.

Dame Ruth also said “planning needs to be improved”. “A number of trusts have attributed operational problems to staffing shortages during half term and the effects of the junior doctor rotation, both of which should surely have been mitigated against.”

An attached spreadsheet shows that just three out of 21 trusts listed hit their February target.

Several were significantly short of the required standard. Barking, Havering and Redbridge Trust reported 77.6 per cent of patients waited less than four hours, more than 17 percentage points under the 95 per cent target.

HSJ has learned that the trust’s interim director of operations Mark Odgen Meade left the trust on Friday. The trust said this was “planned” and due to the appointment a chief operating officer of Cathy Geddes, former interim chief executive of Whipps Cross University Hospital Trust.

North West London Hospitals Trust was 4.6 percentage points short of the same target, Ealing Hospital Trust was 4.6 percentage points short of its local target of 97 per cent, while King’s College Hospital, Whipps Cross University Hospital, University College London Hospitals, and Barnet and Chase Farm were all more than three percentage points adrift of their locally-agreed targets.

Whipps Cross said the figures were inaccurate, but admitted that its performance was under the 95 per cent target.

To hit target for quarter four as a whole, the following trusts will all need to hit a rate of 98 per cent or more: South London Hospitals; Whipps Cross; Barnet and Chase Farm; North West London and Newham.

Barking, Havering and Redbridge’s performance for January and February was so far from target that it now cannot reach a 95 per cent average for the quarter.

The trust’s director of nursing Deborah Wheeler said: “We recognise that there have been real issues with waiting times in our accident and emergency departments in recent months.

“We are working closely with our partners to reduce length of stay on our wards. This includes ensuring that patients can be discharged from hospital and return to their own homes as soon as they are ready.

“We are also working with residential homes to try and prevent unnecessary admissions wherever possible… we are also looking at ways of reconfiguring our bed capacity to create more provision for emergency admissions.”

A spokesman for North West London Hospitals Trust admitted that its emergency department was “an area of considerable concern”, and said that one of its units had seen a 30 per cent increase in emergency activity in three years. A plan is being drawn up to redevelop it.