One of Labour’s largest trade unions is set to affiliate to Momentum after the ruling executive of the Communications Workers Union voted unanimously to join the organisation.

The CWU, Britain’s largest communications union and the fifth largest affiliate to Labour, was one of the earliest backers of Jeremy Corbyn.

Dave Ward, the union’s general secretary, told the New Statesman that “the general election showed the value of Momentum as part of the wider labour movement”, and that the body, which emerged out of Jeremy Corbyn’s 2015 leadership campaign, was now “a major political force in the UK”, saying it had a “key role to play in securing a transformative Labour government”.

The NEC’s vote will now go to a ratifying vote by the CWU’s annual conference.