And in an apparent parting shot, Webster claims working with Daisy is much easier than dealing with the singer.
He said: “Working with Daisy has been a doddle compared to Christina.
“Her only stipulation was that we pick her up for shoots from Wales because she was there with her boyfriend Matt Smith. He was filming Doctor Who.”
Christina has had a tough year in which she has divorced husband Jordan Bratman and seen her music career falter, but her US TV talent show, The Voice, has proved a hit.