By Laura Armstrong Alison Hammond has rejected a huge pay rise to front This Morning four times a week. ITV were desperate to persuade the Brummie presenter to take the helm after Holly Willoughby ’s departure last October. The mum of one and former Big Brother star, 49, already hosts it on Friday. But she has repeatedly refused the top job because she is so busy with other TV work, such as fronting The Great British Bake Off. An ITV source said: “Alison has long been a favourite with bosses. She’s very popular with viewers and celebrities often request her when they appear on the sofa. “She’s…