The BBC has been criticised by the Conservative Party after it broadcast an interview with a Taleban spokesman.
Dr Mahammed Anif told Newsnight that the UK and US had wanted an "excuse" to invade Afghanistan, and foreign armies would be thrown out of the country.
Shadow defence secretary Liam Fox said the interview was "obscene" and accused the BBC of broadcasting propaganda on behalf of Britain's enemies.
The BBC said it was "entirely legitimate" to air the Taleban's views.
During the interview, with the BBC's David Loyn, other members of a Taleban group in Helmand province were also filmed vowing to fight to the death against the British troops.
In the film, broadcast on Wednesday, a Taleban fighter who gave his name as Mullah Assad Akhond said: "We see the English as our enemy since the time of the Prophet Mohammed. They are our enemies now and they were then.
"We will fight them to our death. We will not let them into our country. They can't deceive us about their propaganda that they are here for reconstruction or rebuilding this country."
Another member, Hajimullah Wahidullah, warned that the militant group planned to step up suicide bombings, which until recently had been rare in Afghanistan.
Meanwhile, Dr Anif - who the BBC said was giving his first broadcast interview as an official spokesman for the group - said: "Americans used force and attacked us. They invaded our country and occupied it.
"They killed our women and children. That's why mujahideen want to throw them out of the country.
"Democracy set up under the shadow of B52 bombers and elections held under the shadow of F16s is not acceptable for the Afghan nation."
The spokesman also denied claims that the Taleban had burnt down many schools which they accuse of teaching children non-Islamic values.
Dr Fox said the entire interview had been "obscene".
"I am disgusted that the BBC should broadcast an interview with a Taleban 'adviser' while our troops are being murdered by them," he said.
"The brave men and women of our armed forces rightly feel nothing but revulsion at the BBC's actions.
"We have become used to a non-stop anti-war agenda from the BBC but broadcasting propaganda on behalf of this country's enemies - at a time when our armed forces are being killed and maimed - marks a new low."
In a statement, the BBC said: "It was entirely legitimate for BBC News to broadcast the Taleban's views.
"Reporter David Loyn made the Taleban's intention to increase suicide attacks patently clear.
"BBC News also regularly reports on the British troops and have interviewed their officers and soldiers on many occasions."
Also on Newsnight, defence minister Adam Ingram was asked whether the government believed the war in Afghanistan could be won.
"Of course we do. There are many indications that it is being won," he said.
"Our brave soldiers are bringing peace and stability to that country."
British forces have been in the country since 2001, when they took part in the US-led invasion designed to destroy the al-Qaeda terrorist network.
The Taleban was swept from power and UK troops remained in the country to assist the transitional government as part of the Nato-led International Security Assistance Force (Isaf).
UK forces are now leading Isaf in the volatile southern province of Helmand, where their duty to make the area secure for reconstruction regularly brings them into conflict with Taleban fighters.