The former head of Britain's MI6 foreign intelligence service has criticized Brown's government over mismanagement of funds in the Afghan mission.

"The Treasury has been squeezing the defense budget for approximately eight years," said Richard Dearlove, former chief of the intelligence service on Wednesday, criticizing Prime Minister Gordon Brown's government.

During a speech at Gresham College in London, the MI6 chief from 1999 to 2004, added that the lack of a sufficient budget has left the British armed forces "under-resourced."

"Until recently, our political leadership has failed to explain satisfactorily why we are at war," he added.

However, a Downing Street spokesman dismissed the criticism, saying funding increased from 2.5 billion pounds (2.7 billion euros, 4.1 billion dollars) in 2008-2009 to 3.5 billion pounds in 2009-2010.

Brown has been under mounting pressure over Britain's role in the conflict amid rising troop deaths.

Ninety-eight British service personnel lost their lives in 2009 alone, making it the bloodiest year for UK troops since the Falklands War in 1982.

An increasing majority of Britons want the country's 9,000 troops out of Afghanistan within a year, according to the latest opinion polls.

Some 71 percent of Britons would back a phased withdrawal of British forces within 12 months, a poll conducted by The Independent showed.

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