Labour descended into a state of civil war last night amid accusations of a hard left "plot" to take over the party as the Conservatives extended their huge lead in the polls.

Tom Watson, Labour's Deputy Leader, warned that the future of the party was at risk over claims that a campaign group which backs Jeremy Corbyn is planning to officially link with the union.

Mr Corbyn was heckled at an "explosive" meeting of the Parliamentary Labour Party (PLP) on Monday night, which saw a heated row over the supposed left-wing takeover plot.