'Tidal wave' of unlet office space in London

London faces a 'tidal wave' of unused commercial property as the proportion of unlet office space doubles to 10%, Drivers Jonas has warned.

In its latest half-yearly London construction report the property consultant said that the surfeit of new buildings without tenants would be the equivalent of 14 Swiss Re 'Gherkin' towers between now and 2011.

New speculative office starts have fallen 50% since the last Drivers Jonas report six months ago but 3.26 million square feet of office space is still set to be completed this year.