Senior figures in the British army are arguing that Gordon Brown must give the green light this month to a permanent increase in the number of troops serving in Afghanistan, insisting the UK must make a bigger commitment to defeat the Taliban in Helmand province.

As the US prepares to send 8,000 troops to southern Helmand from May, army chiefs believe the prime minister must give the go-ahead by mid-April for 2,000 extra British troops to be sent to the province in order to reap the maximum benefit from the US and UK operations.