Thurrock, a dock town in Essex, is the ultimate blue-collar seat. Jackie Doyle-Price, the incumbent Tory, has a majority of just 92. Her Labour challenger will be Polly Billington, a former special adviser to Ed Miliband who previously ran for North Tyneside. Illegal migration through the docks is high on the agenda. Tim Aker, Ukip's policy wonk and candidate in the seat, believes the path to victory is in picking up locals' casework over issues such as council housing that he claims his rivals have neglected.