Brexit: UK should rejoin single market as quitting EU ‘biggest piece of self-inflicted harm,’ says Sadiq Khan

Press quote (Evening Standard)
John Springford
29 June 2022
From 
https://www.standard.co.uk/news/politics/brexit-uk-eu-single-market-eu-sadiq-khan-london-mayor-b1009011.html

Another analysis, by the Centre for European Reform, estimated that the UK was being hit with a £31 billion blow to GDP from Brexit in the fourth quarter of 2021.