Sadiq Khan yesterday urged Theresa May to delay firing the starting gun for Britain to quit the EU until after German and French elections next year.
The mayor of London believes this could boost the chances of Berlin and Paris backing a good deal for a post-Brexit UK with the EU.
A delay could mean French and German political leaders being more likely to look to longer-term beneficial ties rather than taking a tough stance as they seek to woo voters.
Khan, who backed a Remain vote and condemned the stance of Westminster’s Brexiters, told Sky News: “I lost the argument and now it’s for them to persuade the EU how we can get the best of both worlds, how it’s possible to have access to the single market and not have free movement of labour.”
“Maybe waiting for French and German elections to be out of the way gives the new French president or German chancellor more of a chance for latitude for some of the things that the British public say we need.”
The prime minister has made clear that she will not trigger Article 50, to start the two-year withdrawal process, before the end of the year.
Khan added: “If we serve notice too quick to quit there’s no guarantee jobs won’t leave.”
He stressed he met the mayor of Milan, Giuseppe Sala, in London two weeks ago and he was “trying to pinch our work”. He added: “I know for a fact there are people from Paris, Berlin, Dublin courting business leaders as we speak.”
But Paul Johnson, director of the Institute for Fiscal Studies which warned of a Brexit blow, stressed the “assumption” was still that the economy will be damaged.
But he again dismissed former Chancellor George Osborne’s suggestion that an emergency budget, which has not happened, would be held to deal with an economic crisis.
An IFS report also concluded that Britain keeping membership of the European Union’s single market could add almost two year’s worth of growth to the economy.
It claimed that membership of the single market could be worth a potential four per cent of extra gross domestic product to the UK compared with World Trade Organisation membership alone.
Ian Mitchell, research associate at the IFS and an author of the report, said: “There is all the difference in the world between ‘access to’ and ‘membership of’ the single market.”
But remaining part of the single market would carry “risks”, particularly for the City, as Britain would have little influence over the rules agreed for the financial and other sectors.