Labour could be decimated in its heartlands on June 8 as Ukip voters switch to voting Tory, according to reports.

Meanwhile, party staff will consider going on strike if Jeremy Corbyn tries to stay on as leader after a heavy General Election defeat.

The party is currently lagging far behind the Tories in the polls with a survey published on Wednesday putting the Conservatives on 49 per cent and Labour on 26 per cent.