Lettings agents say it is the sharpest downturn since the aftermath of 9/11, but this slump is expected to last much longer. Emilie Dawes, lettings director at Marsh & Parsons, said: "The £1,000- to £2,000-a-week bracket - family homes typically occupied by bankers from Europe or America - has definitely been significantly affected. Also hit have been two-bedroom executive apartments, particularly along the Central line. Demand for these is down by 40 to 50 per cent."