A source said Miss Watson's appointment will be announced next month. 'Emma has been excitedly telling friends that she is going to be taking over from Keira.' Emma has been slowly integrated into the Chanel brand. They have been dressing her for film premieres and parties over recent months to see if she is the right fit.

Once it became clear she is growing into a beautiful young woman and wears the Chanel brand so elegantly, they had to sign her up. Chanel realises it is important to target a young audience.' It is understood that Miss Watson's bosses at Warner Bros, which makes the Harry Potter films, have given their full backing to the deal.