It was for this reason that I particularly enjoyed a story I heard the other day about an overseas visitor to Britain who said the best part of his visit had been travelling from Heathrow into central London on the tube.

BBC: The full text of the Queen's Christmas broadcast.

Once Brompton Road is finished, he explained, he will be turning his attention to the abandoned Aldwych station in central London, which has been used for Tube locations in Hollywood films like V for Vendetta, Atonement, and28 Weeks Later.

BBC: Reawakening the Underground

Unfortunately, that still provides no clear guide to how a clash between central government and the mayor over the future of the tube would be resolved.

ECONOMIST: The Greater London Authority

Since central London is quite compact, it may sometimes be quicker to get around above ground than taking the Tube.

BBC: London for disabled visitors