Military experts have criticised the government, saying British forces have been disadvantaged by a lack of proper equipment and support.
Tom King, a former British defence minister, said a lack of adequate air support was causing the high casualty rate.
"Some of the equipment is getting a tremendous bashing out there,” he said.
"Where there really is a critical shortage is helicopters."
The 5,000 British troops in Helmand have just 10 Chinook helicopters compared to the US marines’ 120 in the centre and south of the province.
British troops having to move overland are at greater risk from roadside bombs and improvised explosive devices as a result.
Amadshah Aamadzai, a former prime minister of Afghanistan, told Al Jazeera that the Helmand operation would achieve "nothing but casulaties, killing and bloodshed".
"The only solution is that they should begin negotiations towards peace. No one will gain through fighting, not American, not Afghan, not Taliban," he said.
"This is the right time for both sides to start negotiations and talk about peace."
Colonel Peter Mahoney, the director of a field hospital at the main British base in Afghanistan, said that seriously injured soldiers were being flown back to the UK for treatment.
More than 30 soldiers were taken off the battlefield and treated at the hospital over the weekend, with doctors working round the clock.
"There's no doubt it has been wearing," he said.
He added that medical staff had been warned before the start of Operation Panther's Claw at the beginning of July and extra staff had been mobilised in anticipation of a surge in casualties.
Barack Obama, the US president, said on Saturday the military offensive in Afghanistan had "a long way to go".
"We knew this summer was going to be tough fighting ... we still have a long way to go," Obama told Britain's Sky News channel in an interview.