Despite intense campaigning from UK Prime Minister David Cameron and the Remain campaign, new polling suggests that Brits may vote in favor of leaving the European Union in the fast-approaching referendum on 23 June.

Twin polls released by the Guardian newspaper - one online, the other a telephone survey of 1,000 UK voters - show a shift in opinion towards leaving the EU, with an overall majority of 52 percent.

"It is only one poll but, in a rather unexpected reverse of polling assumptions so far, both our phone poll and our online poll are consistent on both vote intentions and on the EU referendum," said Martin Boon of the ICM group which conducted the polling for the Guardian.

Separately, a YouGov poll showed both sides level on 41 percent, which is unchanged from its previous survey.  But the Guardian results are rattling a few cages.

Much of the "Brexit" drama has been played out among the Conservatives; PM Cameron and those closer to the financial markets want to stay in the EU, while the upstarts and populists like former London Mayor Boris Johnson see opportunity in a Brexit.  The new head of the GMB Union says the Remain campaign needs to engage Labour voters to tip the balance. 

"I think they won't see it as the absolutely crucial vote that it is and I also think that they see it as a bunfight in the Tory party," said GMB's Tim Roache.  "The reality is that the more people that stay at home the more likely it is that we will leave the EU.  I don't think we can even begin to contemplate that."