Overseas visitors to Britain are to be offered free HIV treatment on the NHS for the first time.
Ministers are backing calls for non-UK residents to be treated for the condition as part of efforts to protect the wider public.
Foreign students, workers and victims of human trafficking are among those expected to benefit.
The Department of Health said that safeguards would be introduced to prevent "health tourism".
Currently treatment for HIV is only available to people officially resident in Britain, excluding migrants.
But Lord Fowler, a former Conservative Cabinet minister who has campaigned on Aids, has called for free treatment to be extended to those who have been in Britain for six months.
The proposal, contained in an amendment to the Health and Social Care Bill currently before the Lords, will be accepted by the Government but introduced in a Statutory Instrument rather than as part of the legislation.
The move comes amid concerns about rising levels of HIV infection and the cost to the NHS of not treating it early. Foreigners are thought to be dissuaded from seeking help because of the cost of treatment.
Public Health Minister Anne Milton said: "This measure will protect the public and brings HIV treatment in to line with all other infectious diseases. Treating people with HIV means they are very unlikely to pass the infection on to others.
"Tough guidance will ensure this measure is not abused."
Chief Medical Officer Professor Dame Sally Davies said that effective treatment of HIV reduced its spread by up to 96%.
"This change is in line with the UK Chief Medical Officers' Expert Advisory Group's advice, and offering NHS treatment will encourage testing, resulting in fewer undiagnosed HIV infections and therefore ensuring that there is less chance of passing on infection to the wider population."
Yusef Azad, the director of policy at the National Aids Trust, said: "If someone is tested and treated early, it is much cheaper than them presenting themselves in hospital with a much more serious, complex condition that can cost tens of thousands of pounds to treat."
Department of Health aides said there was little scope for somebody coming to the UK specifically for treatment as the process took months to administer and monitor.
They said the measure would bring England into line with Scotland and Wales, where foreigners can already receive free treatment for HIV without signs of "health tourism" abuse.
Professor Jane Anderson, chairwoman of the British HIV Association (BHIVA), said: "This is good news for people living in the UK who are HIV positive and also for public health in general.
"Access to treatment and care for some of the most vulnerable people with HIV in England has been compromised by the anomalies in the charging arrangements.
"Leaving people living with HIV unable to access the treatment they need makes neither clinical nor economic sense.
"Research shows that proper treatment reduces infectiousness and so stops other people becoming infected.
"It's a decision that will certainly save lives and also improve the quality of life of many who were previously shut out from appropriate treatment."