Gordon Brown today insisted Britain's strategy in Afghanistan was succeeding, despite the bloody fighting which has seen the loss of eight soldiers in 24 hours.
The Prime Minister acknowledged said that the past ten days had been "extraordinarily difficult" for British forces with the deaths of 15 troops since the start of the month.
But in a letter to the senior MPs on the Commons Liaison Committee, he said the Operation Panther's Claw offensive to clear the Taliban from central Helmand was succeeding.
"Despite the tragic losses, morale remains high - and I can report the assessment of commanders on the ground: that the current operations are succeeding in their objectives," he said.
"They are having a marked impact on the Taliban in central Helmand, will improve security for the population in the run up to the elections, and will allow longer term work on governance and development to begin."
In his letter, Mr Brown - who is due to give evidence to the committee next week - acknowledged that the losses of recent days had led to questions over whether Britain could succeed in Afghanistan.
But he said that it was essential that the international coalition saw through its commitment if it was to deny al Qaida a fresh foothold in the country from which they could mount terrorist attacks on the West.
"While I know there are some who have questioned our strategy, I continue to believe our strategy is the right one," he said.
"It has been a very difficult summer and it is not over. But if we are to deny Helmand to the Taliban in the long term; if we are to help Afghanistan and Pakistan to defeat this vicious insurgency and prevent the return of al Qaida - then it is vital that the international community sees its commitment through."
The latest casualties took the total number of British personnel to have died on operations in Afghanistan since 2001 to 184, surpassing the 179 who died in Iraq.
They included five British soldiers from the 2nd Battalion The Rifles who died yesterday in two separate blasts on the same patrol near Sangin, and another British soldier from the 2nd Royal Tank Regiment who died near Nad-e-Ali.
On Thursday two soldiers, one from 4th Battalion The Rifles and the other from Princess of Wales's Royal Regiment attached to 1st Battalion Welsh Guards, were killed in separate incidents.
Mr Brown's intervention comes amid fears in Whitehall that public support for the campaign in Afghanistan is ebbing away in the face of the lengthening list of fatalities.
There has been a concerted effort by ministers in recent days to spell out the importance of the mission to the UK national interest.
Earlier, Foreign Secretary David Miliband said that Britain's future security was at stake in the battle to prevent the country again becoming an "incubator for terrorism" and a launch pad for attacks on the West.
"This is about the future of Britain because we know that the badlands of Afghanistan and Pakistan - that border area - have been used to launch terrible attacks, not just on the United States, but on Britain as well," he said.
"We know that until we can ensure there is a modicum of stability and security provided by Afghan forces for their own people, we are not going to be able to be secure in our own country."
Mr Brown insisted that the Government placed the "highest priority" on the protection of troops, spending £1 billion on extra armoured vehicles over the past three years.
Over the course of that period the additional funding from the Government reserves for operations in Afghanistan had risen from £700 million to £3 billion.
In addition to the equipment out there, he said that more Ridgeback armoured vehicles and Merlin helicopters were on their way.
However Conservative leader David Cameron bitterly attacked what he said was the Government's failure provide British forces with the equipment they needed - particularly the helicopters that would enable troops to move around in relative safety.
"It is a scandal that our forces still lack the helicopters they desperately require to move around in Helmand," he said.
"Promises of more helicopters in the future are not enough. More helicopters are needed today. More helicopters would save lives."Reuse content