An Ordnance Survey spokesman told me the real problem was in Google's terms and conditions which allow the search company, in his words, to "reproduce, modify and distribute content that is entered into their maps." The spokesman said talks had been taking place between the OS and Google about changing those terms, but in the meantime, "We won't allow people to overlay our information onto Google maps. We have to protect our information."
Google and the Ordinance Survey fight over the "last" space, the map.
From the BBC's Rory Cellan-Jones.