The commander of British forces in Afghanistan warned on Sunday night that there would be more UK casualties hours after two soldiers were killed in a battle with the Taliban in the south of the country.

Brigadier Ed Butler said the British presence in Afghanistan was “a very cohesive force and mission” and rejected comparisons with the situation in Iraq. But concern is growing in the UK and beyond that there may not be enough troops to carry out a mission that has had to change to meet the challenge of a resurgent Taliban.