Doctors have warned that they will need more money if they are expected to keep surgeries open for longer hours to suit patients.

Patricia Hewitt, the Health Secretary, had called on doctors to follow the example of the supermarkets, which opened all hours. She said in a speech yesterday to the NHS Alliance: "Although people are very happy with the service they receive from their GP, they are less happy with access and convenience. Patients are telling us with the health service, you either see your GP or, out-of-hours, go to accident and emergency. We need to make sure that GP surgeries become more accessible."

Dr Hamish Meldrum, chairman of the BMA's GPs committee, said the extra hours could not be worked unless the surgeries could hire more staff. "While evening surgeries would suit commuters, they would not suit the needs of young children or the elderly who prefer their practices to be open in the daytime. There are only so many doctors and nurses to go round and clearly there is a limit to the hours each individual can work while still preserving a safe and high quality service for patients."

The shadow Health Secretary, Andrew Lansley, said GPs must be "wondering what on earth is going on". He added: "Only last year the Government agreed a contract with GPs, the result of which was that out-of-hours services were taken out of their responsibility, which meant that Saturday morning were shutting all over the country, which meant that evening services were shutting all over the country."

Ms Hewitt said: "New services may come from entrepreneurial GPs who want to expand ... It is worth remembering that the majority of GPs are self-employed professionals contracting their services to the NHS."