Ali Milani, the British Labour Party's prospective parliamentary candidate in Uxbridge and South Ruislip, poses for a photograph while canvassing in the Eastcote area of London on December 7, 2019. - Ali Milani didn't speak English when he came to Britain from Iran at the age of five. Twenty years later, he's the biggest individual threat to Boris Johnson at this week's election. The 25-year-old candidate for the main opposition Labour party is trying to unseat the prime minister in his Uxbridge and South Ruislip constituency in west London. (Photo by Niklas HALLE'N / AFP) / TO GO WITH AFP STORY BY PAULINE FROISSART