Unison and Unite
With the change in Labour’s electoral system, the unions originally looked set to lose a significant amount of influence in the party. Under the old system, for example, “trade union members and members of other affiliated societies had a third of the votes in the electoral college system”. Nonetheless, they would continue to play an important role within the party, and the 2015 leadership race was no different.
On July 29, The Guardian reported on how Unison, as “one of Britain’s largest trade unions with 1.3 million members”, had officially endorsed Corbyn’s campaign for leader of the Labour Party (just like Britain’s largest trade union Unite). This decision, the paper said, was “a major boost in his campaign”, and would “help to cement Corbyn’s position as… frontrunner”. In the opinion of Unison’s general secretary Dave Prentis, Corbyn’s message had “resonated with public sector workers who have suffered years of pay freezes and redundancies with too many having to work more for less”. Having been “penalised for too long”, he said, the choice of Unison members showed “a clear need for change towards a fairer society where work is fairly rewarded”. At the same time, however, he stressed that the decision was “a recommendation” and that Unison members were “of course free to cast their vote” as they wished.
Corbyn, meanwhile, said “Unison members are in the frontline of the impact of the government’s austerity agenda” and insisted that they provided “the services our society relies on”. For him, these workers deserved to be “valued and heard”. While he had managed to attract the support of Unite and Unison, the GMB union revealed it would not endorse any of the candidates because “there was no clear consensus” within the organisation about who to vote for.
On August 18, Prentis called Corbyn’s rise in popularity a “game changer” for the Labour Party, adding that “references to ‘Corbynmania’ did a disservice” to what he considered “a left-wing re-awakening… sweeping the nation”. He insisted that it was not “just a cult following”, and that it was “across the country”. The fact was, he stressed, that Corbyn was offering real “alternatives” in the straightforward language that citizens wanted to hear. The conflicts within the Labour Party, he claimed, were “being seen through the prism of the Conservative press”, but were not as serious as had been reported”. In his “experienced assessment”, the Labour Party would “not split”.
Communication Workers Union
On July 30, the Communication Workers Union (CWU), which “represents workers in the postal and telecoms sector”, made the decision to back the Corbyn campaign in what was “another major step forward” for the leadership candidate. With 200,000 members, the CWU was “Britain’s fifth biggest union” after Unite, Unison, the GMB, and Usdaw (which had decided to back Andy Burnham).
For CWU general secretary Dave Ward, it was clear that there were “no quick fixes for the Labour party”, but that there were “some easy decisions” (like endorsing Corbyn). “The grip of the Blairites and individuals like Peter Mandelson”, Ward stressed, “must now be loosened once and for all”. In his opinion, there was “a virus within the Labour party”, and Corbyn was “the antidote”. With the “centre ground of British politics” having “moved significantly to the right in recent years”, he argued, the union felt it had to “reject the notion that Labour needs to move to the centre” (i.e. even further to the right).
On August 11, Ward argued that “the world of work has changed dramatically in a short space of time and with the explosion of insecure employment models in recent years, there is a clear need for government to redress the balance of power between employees and employers”. In the interests of putting “people before profits” and counteracting the “worrying growth in zero hour contracts, [the] continued exploitation of agency workers through loopholes in the regulations and [the] growing scarcity in permanent full time jobs”, backing Corbyn was a no-brainer. In Ward’s opinion, the Islington MP was “proposing a solution to a 21st century problem”.
At the same time, the transport and travel union TSSA also endorsed the Islington MP in order to “end the austerity quagmire” and “take the railways back into public ownership”. The general secretary of the “white-collar rail union” Manuel Cortes insisted that the union had decided to back Corbyn because he was “straight-talking” and put forward “sensible policies which resonate with ordinary people” (including a belief that “Labour’s economic policies must move on from failed neoliberalism”).
Final Day Union Surge
On August 12, The New Statesman reported on how a “remarkable 610,753 people [had] applied to vote in Labour’s leadership contest”. After an extension of the deadline “by three hours” until 3pm, the party attracted a whopping “17,755 new members, 99,703 new affiliated members (from trade unions and socialist societies) and 51,295 new registered supporters” in just one day. This “huge surge in affiliated members” suggested that unions had been “holding back members’ details until the last possible moment”. The final figure for those eligible to vote was “299,755 full members, 189,703 affiliated members and 121,295 registered members”. The following day, The Guardian suggested that “around 190,000” of the eligible voters had been “recruited through trade unions, with between 90,000 and 100,000 thought to have come through Unite”.
Unions Say Corbyn Is Electable
On August 21, The Mirror reported that “the leaders of six of the biggest trade unions” had written an open letter insisting that Jeremy Corbyn could “lead Labour to victory in 2020”. It was signed by: “Dave Prentis Unison; Mick Whelan ASLEF; Manuel Cortes TSSA; Dave Ward CWU; Len McCluskey UNITE; [and] Ronnie Draper BFAWU”. A week later, Unite’s delegate on Labour’s NEC Martin Mayer argued that “the Parliamentary Labour Party [had] been out of touch for years”, asserting that Corbyn’s rise had meant “shock and horror for the bully boys” but “joy for everyone else”. On August 30, meanwhile, Unite’s political director Jennie Formby tweeted a critique of Tony Blair’s most recent attack on Corbyn, saying “I totally disagree that neo-liberal multi-millionaire war-mongerer Blair has anything useful to say”. Unite’s John Storey echoed this view three days later, writing that citizens “must stand with Corbyn against media attacks” because “the vast armoury of the Tory press is trained on Jeremy” and had “only just warmed up”.
 http://labourlist.org/2015/07/cwu-announce-theyre-backing-jeremy-corbyn-to-be-labours-next-leader/ and http://www.totalpolitics.com/blog/450691/unions-line-up-to-back-corbyn-as-blairites-branded-a-virus.thtml