A fall in the number of gay and bisexual men using condoms over the past 20 years is responsible for a rise in HIV cases among the group, according to the Health Protection Agency (HPA).
Research by the HPA and University College London shows use of anti-retroviral drugs has helped to stop a sharper rise.
However, between 1990-2010, the proportion of men who have sex with men (MSM), who failed to use condoms increased by 26%.
The latest research, published on Saturday in the Plos One journal, also shows that the number of infections would have been 68% higher without the introduction of anti-retroviral drugs in the same period.
Speaking about the research, Dr Valerie Delpech, head of HIV surveillance at the HPA, said: “Everyone should use a condom when having sex with new or casual partners, until all partners have had a sexual health screen.
“We also encourage men who have sex with men to get an HIV and STI screen at least annually, and every three months if having condomless sex with new or casual partners – and clinicians to take every opportunity to recommend HIV testing to this group.
“Through combining earlier and more frequent HIV testing, programmes that reduce unsafe sexual behaviour and higher levels of antiretroviral (Art) coverage for those requiring it, we could substantially reduce HIV transmission in this group.”
Sir Nick Partridge, chief executive of Terrence Higgins Trust, said: “This research provides concrete evidence of the vital role which condom use by gay men has had in containing the spread of HIV in the UK. Without it, there would have been 80,000 more gay men with HIV between 2000 and 2010.”
According to the HPA, one in 20 gay and bisexual men in the UK now has HIV, rising to one in 12 in London.
New diagnoses reached an all-time high in 2011, with 3,010 cases reported in the group.