London Mayor denounces Brexit cost, calls for rapprochement with EU. Labour Party leader Sadiq Khan stressed the need for "a closer relationship with the EU" He argues that a new deal would "boost our economy and help raise the standard of living of the British people" According to a study commissioned by the City of London, Brexit has already cost the British economy £140 billion (€162 billion), including £30 billion ( €35 billion) for the capital. Cambridge Econometrics also estimates that Brexit has caused a loss of two million jobs in the country, including 300,000 in London.