Maj Gen Barney White-Spunner said the Iraqi-led crackdown on Shia militia groups in Basra had improved security and they would not regain control. He said there was obvious "scope" for the government to review troop numbers.

Maj Gen White-Spunner has just completed a six-month tour of duty as the British commander in the country. He said that he believed conditions were right for the fundamental change to the UK mission in Iraq, which the prime minister outlined in Parliament in July.

Prime Minister Gordon Brown has said the UK's mission will change in 2009, but the Ministry of Defence said it was too early to be specific on reductions.

He said there had been a "marked improvement" in conditions in Basra and the focus of British armed forces was to complete the task of training and mentoring the 14th Division of the Iraqi Army.

But in the first few months of 2009 there would be a "fundamental change of mission" to "make the transition to a long-term bilateral relationship with Iraq", he added.