The majority of older voters, Conservative supporters and men are now backing the campaign to stay in the EU following a collapse in support for Brexit, a new exclusive poll for the Telegraph shows.

The poll finds that the Remain campaign now has a 13-point lead with just one month until the referendum.

The latest ORB poll puts Remain on 55 per cent and Leave trailing on 42 per cent, among people who definitely intend to vote.

Amongst all voters, the Remain campaign now has a 20-point lead, with 58 per cent of voters saying they back the pro-EU campaign.