The Metropolitan Police could struggle to mobilise officers during a terrorist incident because so many live outside the capital – with some based as far afield as Cornwall and the South of France, a new report has warned.

Less than half of the Met’s 18,000 borough officers now live in London, with soaring house prices giving rise to a phenomenon known as "commuter cops”.

According to a report by the Policy Exchange think tank, the trend could make it harder to deploy officers in a major emergency such as a terrorist attack or riot.