He’s the former Marine who served in the special forces, climbs mountains for fun, and now could hold the keys to Downing Street. Following an astonishing interview on Sky News, Al Carns quit as Armed Forces minister over doubts the long-delayed Defence Investment Plan was going to be fully funded. It was yet another blow for a prime minister still reeling from the resignation of his defence secretary John Healey earlier on Thursday. Carns, nick-named ‘Action Man’ because of his military