The deaths have sparked renewed discussions about the purpose of the mission and whether the nation's military has lost its way in efforts to subdue the rugged land that has harbored Osama bin Laden.
But a British military spokesman in Afghanistan said that although they had suffered casualties, they were beating the Taliban and making ground.
"We are holding ground, so we can bring security to the Afghan people and give them some life that is free from the intimidation, misery and violence that the Taliban bring," Lieutenant Colonel Nick Richardson said.
Britain moved into Afghanistan with the United States shortly after the September 11, 2001, attacks as part of a coalition hoping to root out extremism and build a stable government able to upstage the Taliban.
Britain's 8,000 troops are fighting in southern Helmand province together with thousands of U.S. Marines in a major offensive.
It is intended to disrupt Taliban insurgents and cut their supply lines to Pakistan before elections planned for next month.
British Prime Minister Gordon Brown sent a letter to a senior parliamentary committee on Saturday saying that Britain went into Afghanistan in 2001 to tackle the global terror threat. He says that remains the reason to fight on there.
Britain has lost eight soldiers in 24 hours - the highest number to die in a single day since the 1982 war in the Falkland Islands.
In the last 10 days, 15 British soldiers have been killed, one of the worst periods for Britain's troops here.
The deaths pushed Britain's overall toll in Afghanistan to 184, five more than the total British deaths in the Iraq war.