(CNN) -- July is on track to be the deadliest month yet for British troops supporting Operation Enduring Freedom. Air Chief Marshall Jock Stirrup says the sacrifices of British forces are worth it. So far, 15 British servicemen have died in Afghanistan this month, mostly in connection with Operation Panther's Claw, the British-led offensive in Helmand province that is mirroring a similar operation by U.S. Marines in the same area. Britain's deadliest month in Afghanistan so far has been September 2006, when 19 died -- 14 in a single incident, the crash of a Royal Air Force plane near Kandahar.
@highlight
15 servicemen have died this month, compared with 19 in September 2006
@highlight
Most deaths attributed to Operation Panther's Claw in Helmand province
@highlight
Air Chief Marshall says numbers pale in comparison to 197 Taliban deaths
@highlight
Sudden spike triggers outcry in UK, criticism of vehicles used in operations
The sudden spike in @placeholder deaths has triggered an outcry in the United Kingdom over the mission there and whether it will be successful.