There is no such thing as Gulf War Syndrome, an official scientific study has concluded.
Gulf veterans were at greater risk of post-traumatic stress disorder
The Medical Research Council (MRC) said there was "little evidence" the illnesses of campaign veterans were caused by the multiple vaccinations they received.
The government-funded body also said there was no evidence of a link between veterans' symptoms and the use of depleted uranium shells or nerve agents.
But the study was dismissed by the Gulf Veterans and Families Association, which said: "How can the MRC say that Gulf War Syndrome does not exist when it appears in the Royal College of Medicine encyclopaedia?"
The study is a second setback for former UK troops this week, coming days after veterans of Northern Ireland, the Falklands, Bosnia and the first Gulf War lost a compensation claim for the after-effects of trauma suffered in the line of duty.
Although earlier this month the families' association learned it could receive £300,000 of Lotto funding, a move which it claimed as official backing for its campaign to prove Gulf War Syndrome exists.
The MRC report, which reviewed all scientific data into the veterans' illnesses and did not carry out its own medical research, concluded: "There is no unique Gulf War Syndrome."
This review shows there is no case to justify a separate Gulf War Syndrome
It said symptoms suffered by veterans were similar, despite varying exposures to vaccination, nerve agents, oil fire smoke and other potential hazards.
"In short there is no evidence from UK orientational research for a single syndrome related specifically to service in the Gulf," the report states.
The symptoms - which include tiredness, headaches, lack of concentration, memory loss and numbness or weakness - were shared by non-Gulf veterans, the scientists said.
They accepted that Gulf veterans were at increased risk of suffering from post-traumatic stress disorder, but since this affected about 3% of them it could not have caused the illnesses of all those claiming to have Gulf War Syndrome - a much larger group.
"Depression and alcohol are much more important health risk factors," the report says.
Charles Plumridge, a senior Gulf Veterans and Families Association co-ordinator, said: "It is exactly what we have come to expect from the MoD and government-funded research.
"If you look at the record of MoD over the last few years they have only funded research which comes out in their own favour."
Armed Forces Minister Lewis Moonie said the MRC findings would not save the
MoD money, because veterans were paid according to their disabilities.
"This review shows there is no case to justify a separate Gulf War Syndrome," he said.
An MoD spokeswoman added: "Just because the MRC cannot find evidence for Gulf War Syndrome doesn't mean veterans who came back from the first Gulf War in 1991 and fell ill won't be paid out.
"What we dispute is that there is just one syndrome."
The MRC inquiry was launched in 2002 after the MoD asked for expert advice, and reviewed all worldwide research on the illnesses.