The 13 commissioners from the International Olympic Committee's evaluation team will be guests Friday night at a gala dinner hosted by Queen Elizabeth II, the London Telegraph said.
They will also attend the unveiling of a 30-foot statue of an athlete in Trafalgar Square. On Thursday they visited prospective venues, including the proposed site for the Olympic stadium in Stratford, east London.
"What they have said to me is that they are impressed by the passion and enthusiasm and they are also very impressed by the sheer scale of the technical detail that has been examined as part of the bid," Culture Secretary Tessa Jowell told BBC.
Paris is considered the favorite to host the games.