Research from Savills warns of an oversupply of expensive London homes as developers rush to build for rich foreigners.

The research identifies a huge undersupply at lower levels of the market after £7bn of international cash was spent on high-end homes in the capital last year. A fifth of purchases were from Britain. Two-thirds were investors rather than owner-occupiers. Savills found London faces a 50,000 annual shortfall in new homes.