The British will be voting on leaving the EU later this month; "Brexit" is the buzzword for that, borrowing from the neologism "Grexit" when Greece nearly bolted the Euro a while back.
The prime motivators for the Leave camp are net cash flows away from the UK, unresponsive EU politics and a touch (or four) of nativism. Establishmentarians of both right and left are generally in the Remain camp, but both a Tea Party style right and a blue-collar left are often in the "Euroskeptic" camp. The left often wants more big government and more ability to regulate the economy (such that the left wing of French politics is anti-EU, for example) but blue-collar folks are more likely to be harmed by folks from poorer parts of the EU being able to freely move to Britain and compete for jobs.
This left-listing Guardian piece notes that the blue-collar folks (C2DE in UK econ-jargon) are 53-29 Leave while the white-collar block (ABC1) is 50-39 Remain. Blue-collar folks tend to be a bit less cosmopolitan than their betters and more sensitive to the economic effects of a common labor market. The writer, Polly Toyenbee (yes, she's a granddaughter of historian Arnold), bemoans the heaving playing of the nativist card to promote a Leave vote when good leftists shouldn't be making common cause with the Tory's right wing.
However, we're seeing across the board on both sides of the Atlantic where blue-collar folks respond well to nativist pitches; the new nativist ("hard-right" in Eurospeak) parties often draw more from the socialist left than the right. The nativist Freedom party in Austria skewed rural and blue collar, and the German AfD was getting more votes off of the Social Democrats and the neocommunist Left than the mainstream conservative CDU. On our side of the pond, The Donald skews downscale in his support.
That is even more pronounced in a vote that doesn't have a party attached to it. Labour has often lost votes in EU election to the Eurohostile UKIP. Those UKIP voters that vote Labour in House of Commons elections on economic grounds are free to vote to leave, then have a shot a seeing an anti-powers-that-be government manage the more-empowered UK government afterwards.