The worst-hit practices have six times the average number of patients per GP and some patients can wait nine weeks for an appointment

A national shortage of GPs has left some surgeries with one permanent doctor caring for as many as 11,000 patients, a Times investigation can reveal.

Families registered with the worst-hit practices, which have had more than six times the average number of patients per GP, have reported waiting up to nine weeks for appointments.

Elderly patients and parents of young children said they have had to call ambulances or visit hospital A&E departments for problems including chest infections and dizziness because it is so difficult to see their doctor.

The findings, from an investigation into the most severely understaffed practices in the country, come after the NHS was thrust to the centre of the election campaign.

Staff shortages have become the most critical problem