Gordon Brown says Boris Johnson would face an "economic war" with Europe and America if he fails to strike a trade deal.
The former PM said Mr Johnson's confrontational approach will make him the "most isolated prime minister in peacetime history" if there is a no-deal Brexit.
He added: "Because he has simply chosen a path of confrontation when everybody knows that it's in Britain's economic interests - maybe not in the Brexiteers' ideological interest - but it's in Britain's economic interest to get a deal and to get a deal now."
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