Up to one in 10 people are infected with chlamydia

It has named 16 new areas of England which will be covered in a further move towards a national programme.

Ten areas already provide screening for the disease which often has no symptoms, but which can lead to pelvic inflammatory disease and infertility.

Up to one in 10 people are believed to be infected with chlamydia.

The levels of chlamydia in young people are a particular concern Professor Mike Kelly, Health Development Agency

MPs are also set to discuss a critical report from the Common's Health Committee last summer which warned the country was on the brink of an "appalling" sexual health crisis.

The committee's report said long-term underfunding had created a position where NHS clinics were unable to cope with demand.

In September the government pledged more than £20 million to help improve sexual health.

'Under-investment'

Health minister Melanie Johnson said the extension of the chlamydia screening programme meant women in a quarter of all primary care trusts in England would now have access to screening.

She said: "Sexual health services suffered from under-investment over many decades by different administrations.

"We've already ploughed in millions of pounds to support the sexual health strategy - the first ever such action plan in this country. But I know we need to do more.

"We're also planning the third phase of the roll-out. However, in areas where the screening programme is not yet in place, chlamydia testing is still available from genito-urinary medicine clinics, some community contraceptive clinics and GP surgeries."

She said the government would also be carrying out a review of modernisation in genito-urinary services.

Shadow Health Minister Simon Burns MP said: "The country is facing a sexual health crisis that requires urgent and meaningful government attention.

"We have consistently warned the government that, unless proper steps were taken, incidences of STIs would continue to rise.

"Their failure to act properly means that we now face a burgeoning epidemic, that sexual health services are under increasing pressure and that there are dangerously long waits for treatment. "

Priority

The Health Development Agency says better sexual health education will help reduce rates of infection.

Professor Mike Kelly, director of research and information at the HDA, said: "This evidence on what works best to prevent STIs will help us tackle this major public health problem.

"The levels of chlamydia in young people are a particular concern, so the evidence that school-based sex education is effective is encouraging because it helps us to target this age group."

A separate report from the Independent Advisory Group on Sexual Health and HIV welcomed the recent investment into sexual health services, but said clinics needed more money and more staff to cope with demand.