Its research shows half of young men in the UK are planning to celebrate at parties, clubs and pubs this New Year.

Women are more likely to be staying at home or with friends.

Many young people who are going out are hoping that sex will be on the menu. One in 10 men aged 16 to 34 says a new sexual partner is the most important ingredient of a happy new year.

Although most people questioned for its survey said they would wear a condom with a new partner, only 37% said they would actually take condoms with them when they go out for festive celebrations.

The HEA says the highest levels of unsafe sex take place around Christmas, reflected by peaks in abortions, sexually transmitted infections, and people going for HIV tests in the first quarter of each year .

It is predicting a gloomy millennium for many young people if they do not take the proper precautions.

The HEA is launching a safer sex campaign on Thursday, urging young people to stock up on condoms and the contraceptive pill before the long New Year holiday kicks in, and shops and sexual heatlh services close down.

The HEA is encouraging young people to take condoms with them to parties, and use them to avoid sexually transmitted infections and unplanned pregnancy if they have sex with a new partner.

It says one in three 16- to 34-year-olds say they have found a sexual partner at a party.

Alcohol

As part of its campaign, the HEA is also issuing posters and free postcards aimed at young people who go to pubs and clubs, and running safer sex advertising in music magazines and entertainment guides throughout December.

HEA Project Manager Katy Fitzsimon said: "It's clear that a significant number of young people will be out celebrating and looking to meet new sexual partners during millennium celebrations.

People who drink may be more likely to have unsafe sex

"Even though one of the campaign messages urges people only to have sex if they really want to, our research shows that three out of four young people drink heavily at Christmas parties, and that about one in seven young people have had unsafe sex after drinking alcohol.

"At this time of year, an increase in levels of unsafe sex leads to rises in unintended pregnancies, sexually transmitted infections, and worried people seeking HIV tests following the party season.

"This year, extended public holidays between Christmas and the millennium are likely to mean closures to sexual health services and places selling condoms.

We're urging young people to prepare now so they're able to have safer sex if they meet a new partner during the festivities."

The HEA is also asking health workers to remind young people of the need for safer sex in the run-up to New Year celebrations.