Van Outen, who is tipped to receive a six-figure salary for the role, first teamed up with Vaughan from 1996 to 1999 when they co-hosted Channel 4's 'Big Breakfast' television programme.
They teamed up again in 2004 to front the BBC's 'Passport to Paradise' but the series was poorly received.
Van Outen finished her stint in the West End musical 'Rent' late last month.