Two New Polls Show Brexit Ahead: Opinium Shows +19, Guardian Shows +6

The Opinium Poll, commissioned by the Brexit-backing Bruges Group think tank, is further evidence that the Leave camp is gaining support and delivers the biggest margin of victory for Brexit so far, after giving voters the option of a choice of free trade agreements with the EU.

It found 52 per cent chose to leave the EU, with only 33 per cent choosing to keep the status quo.

Despite there being less than two weeks before the crucial referendum, on June 23, a further 15 per cent said they still didn't know.

Support for leaving the EU is strengthening, with phone and online surveys reporting a six-point lead, according to a pair of Guardian/ICM polls.

Leave now enjoys a 53%-47% advantage once "don't knows" are excluded, according to research conducted over the weekend, compared with a 52%-48% split reported by ICM a fortnight ago.

The figures will make grim reading for David Cameron, George Osborne and the Labour party. They follow a fortnight in which immigration became the dominant issue in the referendum campaign, with the publication of official figures showing that net migration had risen to a near-record 333,000 in 2015.