The 150th soldier to be killed in Iraq is expected to be named on Friday.
The soldier, from the 4th Battalion The Rifles, was shot during a swoop in the district of Al Atiyah, north west of Basra in the south of the country.
The victim was airlifted to the main British base in the city but died an hour and 20 minutes later.
The bloody milestone came as Britain's ambassador to Iraq issued a direct appeal for the release of five UK citizens taken hostage in Baghdad more than a week ago.
Rose Gentle, mother of Fusilier Gordon Gentle who died in Iraq in June 2004, said she felt "sick" to hear of the death of the 150th member of British forces.
"I think Gordon Brown should be thinking 'This is the time, this is it, bring them home'," she said.
The figure of 150 includes 116 killed in action and 34 others whose deaths were accidents or linked to natural causes, illness, remain unexplained, or are still under investigation.
The Ministry of Defence said the soldier who died had been taking part in a "search and detention" operation in Al Atiyah when he was shot by small arms fire.
He was airlifted to Basra Air Station for medical treatment but died .
Three other coalition troops were hurt but their injuries are not believed to be life-threatening. Next-of-kin have been informed.
