Wayne Bass said his life has been ruined by the condition that could have been prevented had he been given antibiotics to protect him from the disease.

His case tests the MoD’s duty to protect against Q fever, which is linked to exposure to animal excrement.

Mr Bass believes he contracted Q fever in 2011 while deployed in Afghanistan’s Helmand Province.

Humans usually catch the infection from breathing in dust from the faeces of infected animals, typically cattle, goats and sheep.

“To avoid enemy fire I was constantly having to dive into ditches on the ground where farm animals had been, there were animals all over the place,” he said.

Intravenous antibiotics failed to cure his condition and he was diagnosed with Q fever chronic fatigue syndrome, a rare development.

“On some days I’m OK, I can walk a few hundred metres but often I get breathless, have aches and pains all over my body for which I have to take very powerful painkillers.

“The nerve pain in my lower back and legs means that my back can lock up and I’m immobile.

“On a less bad day it can take 45 minutes to walk 600m,” he added.

Justin Glenister, a partner at Hilary Meredith, the firm representing Mr Bass thinks the case could be a landmark one.

“This is the first case in which the question will be asked whether the MoD had a duty to protect soldiers against this known risk of Q fever, which we say was a preventable risk, and what steps it ought to have taken to protect them. There are other similar cases being prepared.”

The MoD’s defence revolves around the low risk of contracting Q fever and the fact that only a third of the 200 people who contracted in between 2008-11 were symptomatic cases.

Mr Bass argues the Army should have provided doxycycline to protect him from Q fever.

However, the MoD has said this would be unreasonable given as the drugs compromise the effect of anti-malarial medicines given to soldiers.

The five-day trial will conclude on Friday.