You are either looking at a serviced apartment, but you ain’t gonna find much under £100 per day.
However, that isn’t much more expensive than a reasonable hotel room in London.
See (example): http://www.short-lets.co.uk/
… or a hotel room with cooking facilities
Eg http://www.travelstay.com/pages/Dyla...htm?affcode=RA £35pp
http://www.travelstay.com/pages/Earl...htm?affcode=RA £24pp
Look at others under http://www.travelstay.com/London_Rooms.htm
Enjoy !
