Some Gulf veterans have suffered from various complaints
An independent inquiry has backed Gulf War veterans claims that some did suffer ill-health as a result of their service in the 1991 conflict.
What has this inquiry found?
Headed by former law lord Lord Lloyd of Berwick, the inquiry said the Ministry of Defence should accept that veterans have suffered ill-health directly linked to their time in the Gulf.
It called on the MoD to provide compensation payments to those whose health has been affected.
The inquiry's report said all the scientific studies had shown Gulf veterans were twice as likely to suffer from ill health than soldiers who had been deployed elsewhere.
Lord Lloyd said all potential causes were related to the veterans' service, and "no other possible causes had been proposed".
He also said that although the illnesses suffered by veterans were probably caused by combinations of different factors, it would not be medically incorrect to describe their ailments collectively as a syndrome.
The inquiry was set up after the MoD had refused to hold an official inquiry.
What is the Ministry of Defence's standpoint?
It continues to deny the existence of Gulf War syndrome.
The MoD argues that there was no single cause of the illnesses reported by veterans from the conflict.
However, it produced its own report earlier this month in which it accepted it had not been open about the vaccinations it had given troops in case of a biological or chemical attack.
So what do veterans claim Gulf war syndrome is?
Ex-soldiers and navy and air force personnel report mood swings, memory loss, lack of concentration, night sweats, general fatigue and sexual problems.
Veterans have also suffered from cancers, motor neurone disease and stress disorders.
Tony Flint, of the National Gulf War Veterans and Families Association said: "What we're hoping is that this inquiry will vindicate what we have been saying for the last 13 to 14 years; that there is a Gulf War Syndrome."
How many veterans believe they suffer from the syndrome?
Support groups claim about 6,000 veterans have suffered unexplained poor health since the 1991 war.
What do the troops think caused their medical problems?
The theories broadly fall into three categories - vaccines, chemicals and weapons.
Before fighting the war, military personnel were given multiple vaccines, sometimes as many as five a day, to protect them against a range of dangers, including anthrax and the plague. Critics say the troops' immune systems were overloaded.
But there have also been suggestions nerve agents from Iraqi chemical weapons storage facilities, pesticides used locally in Iraq and exposure to pollution from burning oil wells could have caused the ill-health.
The use of depleted uranium (DU) in weapons - military commanders favoured it because of its ability to punch through armoured vehicles - has proved controversial. The Gulf war was the first case where DU, which is radioactive, was used on a significant scale.
Some scientists believe a combination of these factors could have caused the ill-health.
What research has been carried out?
There has been a number of inquiries and studies in recent years, giving a variety of conclusions.
The most recent was published last week by the US Veterans Department in Washington saying there was a "probable" link between illnesses suffered by American veterans and exposure to toxins, including nerve gases such as sarin.
The strongest evidence in favour of the syndrome was reported by the New York Times newspaper in October 2004. The US government-appointed Research Advisory Committee on Gulf War veterans' illness said, according to leaks, the syndrome did exist and exposure to certain substances in the Gulf may have altered some troops' body chemistry.
A 2002 study by the Gulf War Illness Research Unit in London also found the poor health suffered by the veterans could not be explained by mental health problems. In a study of 200 Gulf war veterans and 130 soldiers who had served in the Balkans and other conflicts, the team found those who fought in the Gulf were no more likely to suffer anxiety or post-traumatic stress.
However, a US Institute of Medicine study found there was insufficient evidence to determine there was a link between low level exposure to sarin and long-term neurological effects.
And in May 2003 the Medical Research Council (MRC) said there was no such thing as Gulf war syndrome.
The study 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 DU shells or nerve agents.
The London School of Hygiene and Tropical Medicine published its study of more than 40,000 former soldiers in July. It concluded that the soldiers were more likely to report symptoms, but that similar symptoms were reported by both those who served in the Gulf, and those who did not.
What have the veterans done to push their case for recognition?
The British Legion first called for a public inquiry into the illnesses surrounding the 1991-1992 Gulf War veterans seven years ago.
Some veterans have taken their case to court. In May 2003, ill veteran Shaun Rusling won an appeal after he was denied his army pension. An appeal court ruled that Gulf War syndrome did exist - and was caused by active service.