Britain is to send between 1,000 and 1,500 fresh troops to Afghanistan to help fight insurgent Taliban forces in the south of the country, the Financial Times understands.

In a brief statement on Friday evening, after newspaper reports of the planned deployment, Des Browne, defence secretary, confirmed that the UK would “provide some additional forces for the southern region”. They are expected to be highly mobile units able to be deployed across a wide area, a Whitehall source said.