The 1999 Global Youth Sex Survey also found that people are losing their virginity earlier than ever before, and that they are taking more risks - many of those questioned in the UK would get drunk before sex and not use contraception.

While the UK's youth were fairly sex mad - they ranked it second in importance to money - they expect to get bored, saying their enthusiasm will fade with age.

The survey, which questioned 4,200 16 to 21 year olds, examined sexual habits in 14 countries.

Young Britons claimed they make love an average of 133 times a year - leaving the US in second place on 128 and Germany third at 116.

This compared to Mexico and Singapore, which on 66 and 63 respectively came bottom of the table and had sex only half as frequently as those at the top.

On the whole, men were likely to have had more sexual partners than women and the US topped the table with an average of 7.5 partners by the age of 21.

The UK was next with 6.4, followed by France on six, Singapore on 5.6, Canada on 5.5 and Germany hitting the global average of 4.9.

Dutch courage: Many get drunk before sex

However, some of the responses on contraception would worry sexual health specialists - although the implication that people should buy more condoms is not going to worry the survey's sponsor, Durex.

Sixteen per cent said that they had not bothered with contraception for their first sexual encounter because they were too drunk to worry.

While 60% said they had changed their sexual behaviour because of the risk of HIV and Aids, a third said they knew someone with a sexually-transmitted disease.

Knowledge gap

Yet knowledge was poor in some areas, with less than half the sample knowing that condoms can prevent transmission of chlamydia - a disease that can cause fertility problems.

There was also a worrying blow to the government's efforts to prevent younger teenagers having sex.