The broker calculates that take-up in the second quarter was 1.95 million sf, bringing the total so far this year 3.25 million sf. At an annualised rate of 6.5 million sf this is below the average more than 10 million sf per annum over the last ten years. The limited letting activity is producing very little hard evidence of rents, but JLL puts top West End rents at £75 ($117) per sf and top City rents at £60.00 ($94) per sf.

But the picture is different in the investment market. The second quarter saw investment turnover of £2.2 billion ($3.4 billion), treble the level of the previous quarter.

JLL's International Director of City Investment Julian Nairn said: "The Central London investment market is likely to remain very strong with the considerable weight of money overhanging the market from UK and German institutions, banks and a wide range of property companies and private investors exceeding the supply of available properties. The strength of the investment market is surprising at a time of a weak leasing market which has an adverse effect on rental growth prospects; it is a consequence of low interest rates and poor performance in the equity markets."