London is suffering a supply squeeze on office space, figures from property adviser Deloitte show.

More than a third of property under construction has been let and the amount of high-quality space available has halved in the past four years. Technology, media and telecom groups are driving demand, pushing office rents higher and fuelling the shortage of high-quality space. Their share of total office lettings has climbed from just 8% in 2007 to a high of more than a third last year. Deloitte warned that demand for space is forecast to be twice the amount of new space under construction in the next two years.