The sister of Prime Minister's wife Cherie Blair has told how she had been given "potentially fatal" advice by the Government's NHS Direct telephone health line while suffering a miscarriage.

In the latest issue of New Statesman magazine, Lauren Booth condemns the advice service, launched last year, as a "placebo for hypochondriacs".

She told how a miscarriage three weeks ago had left her in agony and unable to get to her GP because she felt so weak.

Ms Booth called NHS Direct but a "disembodied voice" told her to see the GP.

She added: "I held on another 24 hours and then, in tears, I again tried the phone line.

"I waited for my call to be returned and rerouted. Finally a reassuring lady, who had 'been through the same thing, dear' advised that I curl up with a hot water bottle."

Ms Booth added: "Two hours later, I was rushed to an emergency ward and placed on a drip, suffering from a suspected ectopic pregnancy. Staying in bed with a hot water bottle had been potentially fatal advice."

In the article, Ms Booth said the Government's "spin" about the new service has "clouded" what it can offer.

She said it did not offer faster than normal help to people who are seriously injured nor instant access to a doctor.

Ms Booth also claimed that people in the NHS said there had been other serious cases of misdiagnosis, including a man told to take paracetamol when he had a serious case of malaria.