Looking for June 6 - 9th 2010. Right now I'm seeing a few different ones:

Grosvenor House, A JW Marriott Hotel (299 GBP), or
Renaissance London Chancery Court Hotel (285GBP),
London Marriott Hotel Grosvenor Square(310GBP) or
London Marriott Hotel Marble Arch (229GBP).

These are my preferred ones in London, let me know. Thanks for any help!