Britain is considering what military assets could be sent to Afghanistan

The SAS has been readied to return to Afghanistan in significant numbers as part of Donald Trump’s planned military surge after British intelligence helped persuade the US to step up the fight against the Taliban.

Senior sources in the military and Whitehall say Theresa May is prepared to approve a surge of special forces personnel to hunt down Taliban leaders and the Isis and al-Qaeda militants they are sheltering.

The Sunday Times has learnt that SAS and Special Boat Service operatives have a key role in a “scoping exercise” to consider what military assets could be sent to Afghanistan.

No formal request has been received from the Americans, but ministers expect the Pentagon to ask for the SAS to support a surge in US special