Boris Johnson is making promises he cannot keep, says leadership rival Stewart

Boris Johnson is making promises over Brexit he will not be able to keep if he wins the contest to become Prime Minister, one of his rivals for the top job, Rory Stewart, said on Wednesday.Former foreign minister Johnson, front-runner in the race to succeed Theresa May, officially launched his campaign earlier on Wednesday with a commitment to lead Britain out of the European Union on Oct. 31."In a leadership contest of fairytale tax cuts and unworkable pledges, this promise to get a new deal or