Health workers should be sent into clubs and bars to encourage young people to have medical check-ups for sexual diseases, an influential committee of MPs will tell the Government this week.

A hard-hitting report from the Health Select Committee will warn that a different approach needs to be taken to providing sexual health services, in order to alert a new generation to the dangers of having unprotected sex.

Infection rates of chlamydia, gonorrhoea, herpes and thrush are soaring among young people, who are having sex at ever younger ages and not using condoms.

The report will recommend that the Government implement a nationwide screening programme for chlamydia, an infection that is the most common cause of infertility in women but of which most people know little because it has so few symptoms.

But the MPs also want a different approach to the prevention of disease. They would like to see health workers encouraged to go out to clubs and places where teenagers meet, to give them messages about safe sex and to tell them about where they can go to be tested for disease.

The recommendation is likely to prove controversial, because some campaigners will see it as interference from staff who should remain within health clinics.

But the scale of the problem is not in doubt. Rates of chlamydia increased by 108 per cent from 1996 to 2001, and the infection is estimated to affect one in seven girls under the age of 16 and one in 10 women. About 5 per cent of sufferers develop pelvic inflammatory disease (PID), which can scar the Fallopian tubes and leave them blocked, leading to infertility.

A recent survey suggested that one man in 10 is a carrier, but 90 per cent of them will have no symptoms; the other 10 per cent suffer little more than a mild irritation.

MPs on the committee, who publish their report this Wednesday, have been convinced after taking evidence from experts that there needs to be an immediate screening programme for chlamydia, so people can receive antibiotics.

The Government has had two pilot projects for a screening programme which have shown some success.

About 95 per cent of those diagnosed with chlamydia returned for treatment. They now plan to roll this out to 10 other sites around the country, but the committee wants to see the programme go nationwide. The current scheme offers testing to women aged between 16 and 24.

A nationwide screening would cost about £96 million a year, which is currently twice the amount that the Government is setting aside for its entire sexual health strategy. But that cost would be offset by the expense of treating the problems that are being caused by chlamydia, such as infertility and ectopic pregnancies.

The Chlamydia trachomatis bacterium can be sexually transmitted and cause inflammation in the uterus, which may then block the Fallopian tubes, a condition known as salpingitis. When it turns to PID, a woman can develop chronic pelvic pain and irregular periods.

Another study recently showed that it may also be linked to ovarian cancer.

A recent study by doctors at the Edinburgh Royal Infirmary found that almost 10 per cent of 800 men aged between 16 and their late twenties tested positive for the disease.

The finding surprised medical experts, as previous studies had suggested that only one man in 50 was infected. It has led to doctors recommending that men should also be tested for the disease.

There is a waiting list of two to three weeks at some clinics, although treatment should be immediate in order to minimise the risk of trans mission. More than one million people a year now need an appointment, a doubling of the numbers over a decade.

Earlier this year David Hinchliffe, chair of the Health Select Committee, said: 'The whole sexual health service is a shambles. Professionals are crying out for help and not getting it. I do not use the word crisis lightly, but I think we have a crisis here.'

Some experts believe that the safe-sex messages of the Eighties have been lost on today's teenagers.

Cases of gonorrhoea have risen by 86 per cent in the past five years. Syphilis is also making a comeback.

Professor Michael Adler, the Government's adviser on sexual health, said: 'Sexual health is not an NHS or political priority. Until it becomes so, we will witness further failure upon further failure.'