Plans are being drawn up for the RMT (the National Union of Rail, Maritime and Transport Workers) to reaffiliate to the Labour Party in the wake of Jeremy Corbyn’s significant gains in the general election, the New Statesman has learnt.

The union, which represents tube drivers and other workers across the transport sector, was expelled from the Labour Party under Tony Blair after some Scottish branches voted to support the Scottish Socialist Party instead.

But the RMT endorsed both of Corbyn’s bids for the Labour leadership and its ruling national executive committee backed a Labour vote on 8 June.

Corbyn addressed the RMT’s annual general meeting in Exeter yesterday, where he was “given a hero’s welcome”, in the words of one delegate. Mick Cash, the RMT’s general secretary, praised Corbyn as the union’s “long-term friend and comrade”.

After the meeting, Steve Hedley, assistant general secretary at the RMT, posted a picture to Facebook with John McDonnell. The caption read: “With the shadow chancellor John McDonnell arguing that we should affiliate to the Labour Party after consulting fully and democratically with our members”.

The return of the RMT to Labour would be welcomed by the party leadership with open arms. And although its comparably small size would mean that the RMT would have little effect on the internal workings of Labour Party conference or its ruling NEC, its wide spread across the country could make the union a power player in the life of local Labour parties.