Len McCluskey Unite union leader
Len McCluskey, General Secretary of Unite, speaks at a Jeremy Corbyn campaign event at the Rock Tower on September 10, 2015 in London, England Rob Stothard/Getty Images

Leaders of three of the biggest unions in Britain – Unite, UNISON and the PCS – have pledged support to newly-elected Jeremy Corbyn. The left-leaning Islington North MP won the race for the Labour leadership today by securing almost 60% of the votes cast and a number of key unions have voiced their support for the long-serving MP.

The former backbencher of 32 years standing, Corbyn will address the Trade Union Congress (TUC) on Tuesday expecting a rousing reception. Unite general secretary Len McCluskey, who appeared at rallies with him during the contest, welcomed the result of this morning's ballot.

He told Sky News: "Unite members were among those who took part in their thousands, enthused by the chance to engage in a genuine debate about what and who Labour stands for, and the sort of nation we want modern Britain to be," he said.

"The Corbyn team deserves particular credit for inspiring young and old alike, for pointing the way towards how Labour can transform itself to once again be the people's party. Voters can now look at Labour and see, unquestionably that it stands for fairness, justice, peace and strong communities.

"It is the party of hope, ready to take on a government hell-bent on making life worse for ordinary people. The task now for all of us who support Labour is to back the leadership team, to unite, to turn to face the Tories and hold them to account."

Dave Prentis
Dave Prentis, the general secretary of Unison. Reuters

UNISON General secretary Dave Prentis, also expressed his delight at the result of the Labour leadership ballot. "Today people for the first time in a decade are hearing a message of hope," he said.

"People see in Jeremy a politician who has created a wave, a vision of a better, kinder world that works for everyone, not just a self-serving few‎. This is a chance to claim back the heart and the soul of the party and make it our Labour Party once more‎."

But Sir Paul Kenny, leader of the GMB union, said that Labour had reduced the participation of union members when they began to accept registered supporters. He said: "This is a historic moment in British politics.

"There is now a clear division between the parties. No longer will anyone be able to say that they are all the same. It was New Labour that pushed for registered supporters to dilute the influence of the votes of union members.

"They have been successful in reducing the participation of union members but on the registered supporters it may be careful what you wish for. Jeremy has a massive job to do. It is one thing to win votes in a leadership election. It will be a much bigger job to win back the support of the millions who stopped voting Labour."

And ITV reports that Public and Commercial Services (PCS) union general secretary Mark Serwotka said Mr Corbyn's campaign had been "incredible". "This is an absolutely stunning and well-deserved victory, crowning an incredible summer that has shaken the cosy consensus that has infected our politics," he said.