The chief executive of Goldman Sachs has warned that London’s financial centre will “stall” due to the turmoil of the Brexit process. Lloyd Blankfein, who runs the world’s second-largest investment bank, said a three-decade expansion that has turned London’s financial services sector into a world leader could grind to a halt. “It will stall, it might backtrack a bit, it just depends on a lot of things about which we are uncertain, and I know there isn’t certainty at the moment,” Blankfein said in an interview with the BBC. “I don’t think it will totally reverse.” Blankfein also said there would need to be an implementation period of at least a “couple of years” after the Brexit deal had been agreed in early 2019 to allow companies to adjust. “We are talking about the long-term stability of huge economies with hundreds of millions of people and livelihoods at stake, and huge gross domestic product,” he said. “So, if it takes a little while, I’d rather get it right than do things quickly.” If not enough time were factored in, banks such as Goldman would have to act “prematurely” and possibly move some of their operations and jobs.