The 66-year-old, whose policies have been compared to those of radical leftist Greece's Syriza and Spain's Podemos, won after clinching 59.5 percent of the vote, giving Britain its most left-wing leader in decades among the main parties.
The new Labour chief could divide Britain's biggest opposition party, and he immediately faced shadow cabinet resignations amid warnings from party grandees that Labour could be consigned to electoral oblivion.
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