LONDON - Britain's opposition Labour will do everything it can to prevent the country leaving the European Union without a deal, the party's leader Jeremy Corbyn said on Sunday. Boris Johnson took over as prime minister on Wednesday with a pledge to deliver Brexit by Oct. 31 'no ifs or buts' and the government is ramping up preparations for a 'no-deal' exit. 'We will do everything to prevent a no-deal exit and we will do everything to challenge this government,' Corbyn told Sky News. Asked about the prospect of pushing for a no-confidence vote in the government, Corbyn said he would 'look at the situation' when parliament returns from its summer break in September.