Giving women the contraceptive Pill without prescription will not cut the number of unwanted pregnancies, a health expert says today.

Dr Sarah Jarvis, women's health spokeswoman for the Royal College of GPs, said failure to take the Pill regularly contributed to the UK's high rate of unintended pregnancies.

Making it easier to get the Pill will also not reduce the UK's teen pregnancy rate, which is the highest in western Europe, Dr Jarvis says. She prefers long-acting contraception, such as implants or intrauterine devices.

Lambeth and Southwark primary care trusts in London are to run pilot schemes allowing women to obtain the oral contraceptive without a GP prescription. The scheme could be rolled out across England.

Writing in the British Medical Journal, Dr Jarvis said low use of long-acting contraception in the UK was one reason for high rates of unwanted pregnancy.

"About 8% of women of childbearing age in the UK (with a 15% teenage motherhood rate) use long-acting contraceptives, compared with about 20% in Sweden, where the rate of teenage motherhood is 4%," she said.

She went on: "Compliance is low with oral contraceptives. In one study, 47% missed one or more pills per cycle, and 22% missed two or more. Teenagers are the group with the highest non-compliance."