An independent public inquiry is to be held into the supply of contaminated NHS blood to haemophilia patients.
Many people have died
More than 4,500 people were infected with HIV and hepatitis C during the 1970s and 1980s after being given contaminated blood products.
More than 1,700 patients have since died, and many more are terminally ill.
The inquiry will be led by Labour peer Lord Archer of Sandwell, a former Solicitor General. A similar probe has been ruled out in Scotland.
However, the inquiry will be funded privately, and not by the government.
Despite intense campaigning for 20 years, successive governments have previously ruled out a public inquiry.
The Labour peer Lord Robert Winston described the situation as "the worst treatment disaster in the history of the NHS".
Lord Archer is charged with investigating the circumstances which led to patients receiving contaminated blood products, and with recommending ways to address both their problems and those of bereaved families.
Roddy Morrison, chairman of the Haemophilia Society, said: "An entire generation of people with haemophilia have gone unheard.
"All across the UK those infected and their families will rejoice that all the facts are finally to be brought out into the open."
Mr Morrison said many patients had suffered financial hardship, and some had lost their homes.
Many more had found themselves to be uninsurable, unemployable and unable to make adequate provision for their dependants.
Haemophilia is a rare inherited bleeding disorder in which blood does not clot normally.
The main problem is internal bleeding into joints, muscles and soft tissues.
Currently, the condition can only be treated by injections of the clotting chemical, known as factor VIII.
Explaining the government's refusal to fund an inquiry, a Department of Health spokesman said: "We have great sympathy for those infected with Hepatitis C and HIV and have considered the call for a public inquiry very carefully.
"However, the government of the day acted in good faith, relying on the technology available at the time, and, as all the information is in the public domain, we do not feel that a public inquiry would provide any real benefit to those affected."
Scotland's health minister Andy Kerr has again ruled out a government-funded public inquiry north of the border.