Thousands of people will contract a sexually transmitted infection this weekend, campaigners have warned.
Condoms can protect against STIs
Officials behind the NHS 'Sex Lottery' campaign say there will be 1,440 cases of chlamydia, 572 cases of genital warts and 207 cases of gonorrhoea.
They are distributing 50,000 condoms in pubs and clubs this weekend in an effort to encourage people to practise safe sex.
Using a condom can reduce the risks of a range of STIs.
Figures released by the Health Protection Agency in July showed that the number of people being diagnosed with an STI in England, Wales and Northern Ireland is continuing to rise.
Cases of chlamydia - the most common STI - jumped by 9% last year.
The number of people who were told they had syphilis increased by 28%.
Overall, 708,083 people in England, Wales and Northern Ireland were diagnosed with an STI in 2003.
The Sex Lottery campaign, first launched in 2002, aims to increase awareness of the risks of contracting an STI through unsafe sex.
A new series of saucy postcards is being launched this weekend to try to boost awareness further.
The Department of Health said it was keen to get the safe sex message out over the bank holiday weekend.
"With recent statistics showing an increase in STI rates, the Sex Lottery has launched a dedicated summer campaign to help raise awareness of the risks of unprotected sex," said a spokeswoman.
"The message is clear this bank holiday weekend - don't play the Sex Lottery, use a condom."
The fpa, formerly the Family Planning Association, welcomed the move.
"Raising more awareness about safe sex and distributing free condoms is great," a spokeswoman told BBC News Online.
However, she said the Department of Health should also be doing more to help those who believe they may have contracted an STI.
Many people who suspect they may have an STI can wait weeks to be seen at NHS genito-urinary clinics.
The number of people visiting these clinics has soared in recent years and the NHS is struggling to cope.
A recent survey by the fpa suggested that one of the problems is that the clinics are not open long enough.
It found that over half the 256 clinics across the UK said they were open for less than 21 hours a week.
It also revealed that 16% of clinics had actually cut their opening times compared with two years ago. In addition, just two new clinics had opened across the UK since 2002.
"If someone tries to go to a clinic and doesn't get seen, the chances are they will not be back," the fpa spokeswoman said.
"They carry on having sex and can transmit their infection to others.
"There needs to more investment in these clinics so that people who suspect they have an STI are seen in a timely fashion."