Boston GP Richard Gent said despite a review last summer "little concrete action" has been taken in many areas.

But East Lincolnshire Primary Care Trust said patient complaints had reduced considerably.

Under the scheme, home visits by doctors have been largely replaced with paramedic visits, telephone advice and visits to emergency centres.

While (staff dedication) has not served to hide the problem, it has made it less of a threat to most patients GP Richard Gent

But the trust has made clear a GP is still available to make home visits where "clinically appropriate".

Concerns over patient care led to a review by the Independent Healthcare Commission, which asked managers to monitor the system more carefully.

But the e-mail said there was "no evidence to show that we are actively seeking patients' opinions and responding to concerns".

It also said there was "no systematic monitoring of progress" of the actions being taken to improve the system.

Last year some doctors said the service could be putting patient safety at risk.

One local GP said patients had complained about slow response to queries and long waits at hospital emergency centres.

Dr Gent, who is part of the group which advises the trust on the out-of-hours-service, said he did not leak the email but confirmed it was genuine.

He said the weaknesses of the system, mostly administrative, were compensated for the by dedication of staff.

He said: "While this has not served to hide the problem, it has made it less of a threat to most patients."

The trust said it is working with its board to identify and address any problems with the scheme.