Some 1,300 people, most of them haemophiliacs, caught Aids as a result of such transfusions and approximately 500, many of them children, have died.

Former Prime Minister Laurent Fabius, former Social Affairs Minister Georgina Dufoix and former Secretary of State for Health Edmond Herve will be tried at the Court of Justice of the Republic, which is specially empowered to try former ministers.

Charges

The court's investigating commission has ruled that the three should face charges of "manslaughter and causing accident injury."

Ms Dufoix's lawyer Bernard Cahen said she would face three charges of manslaughter and two of causing accidental injury.

Patrick Maisonneuve, acting for Mr Herve, said his client faced seven charges, including five for manslaughter.

Legal wrangle

The decision follows a six-year legal wrangle over the scandal, which took place during the mid-80s.

The introduction of Aids tests were allegedly delayed

Mr Fabius's Socialist administration, in office in 1984 and 1985, is accused of allowing the use of Aids-contaminated blood products while delaying the introduction of a US test for screening donors' blood in favour of one then being developed by France's Pasteur Institute.

There is also evidence of a decision somewhere in the chain of command to use up old blood stocks.

Poisoning investigation

Mr Fabius, current speaker of the National Assembly, and his two former ministers, were placed under investigation in 1994 for complicity in poisoning.

But France's top appeals court ruled earlier this month that poisoning charges could only be upheld if there was an intent to kill.

Jean-Francois Burgelin, prosecutor of the Court of Justice of the Republic, recommended that the case be dropped completely, but his plea was rejected by the commission.

Mr Fabius and his former colleagues claim they never knowingly approved the use of contaminated blood, but Mr Fabius has repeatedly urged for a court hearing to clear his name.

Mr Herve 'stupefied'

Mr Herve said in a statement that he challenged the decision to place the three on trial.

"I am stupefied," he said, adding that the ruling went against earlier judicial recommendations.

The scandal began in 1990 when an official report said public health officials had allowed blood supplies contaminated by the Aids virus into circulation as late as September 1985, despite contamination warnings issued since December 1984.

Some 30 health and blood-bank officials have already been tried and sentenced in the scandal over apparent attempts to allow Pasteur to produce a screening test to rival that of US drug company Abbott.