In a sharply critical reference to the MoD, the tribunal said it was "highly regrettable" the ministry had dismissed the possibility of such a syndrome. "One wonders whether the acceptance may have been earlier by at least one year if they had attended and given evidence at the Lloyd inquiry."

An independent inquiry under Lord Lloyd concluded earlier this year there was such a thing as Gulf war syndrome. He urged the MoD to start negotiations for payments to up to 6,000 sick former and serving service personnel as the first stage of reconciliation with veterans.

Yesterday's ruling, by a statutory tribunal, will place renewed pressure on the MoD to respond more positively to claims made by Gulf war veterans.

The case was brought by Daniel Martin, an army medic in the 1991 Gulf war. His lawyer, Mark McGhee, of the firm Linder Myers, described the landmark ruling as "fantastic" and a "judicial recognition of Gulf War syndrome".

The tribunal suggested the syndrome could be defined by a collection of symptoms, not by a specific cause. It heard evidence from medical specialists, and found that Mr Martin "suffers from a number of conditions which fall under the umbrella of GWS [Gulf war syndrome]".

Veterans have been trying for years to persuade the MoD to acknowledge the existence of a collection of symptoms, if not a single identifiable disease, attributable to service in the Gulf war, including cocktails of vaccinations and inoculations against chemical and biological attacks.

The MoD last night had no immediate response to the tribunal's ruling.