REUTERS/Neil Hall/File Photo
Britain's Opposition Labour Party leader Jeremy Corbyn attends a Stand Up To Racism rally in London, Britain October 8, 2016.
Clinton, the husband of presidential hopeful Hillary, told a private meeting that Labour made a huge mistake in electing a left-wing candidate and should have chosen a moderate like David Miliband, according to a transcript obtained by WikiLeaks.
The transcript was attached to an email that was sent in October 2015, a month after Corbyn was first elected to replace Ed Miliband as opposition leader.
WikiLeaks published the email as part of a series of leaks relating to Hillary Clinton's campaign manager John Podesta, referred to as The Podesta Emails. WikLeaks is an international organisation that publishes confidential information which often concerns high-profile public figures like politicians.
Clinton allegedly told an audience (emphasis ours):
"If you look all over the world - the British Labour Party disposed of its most [inaudible] leader, David Miliband, because they were mad at him for being part of Tony Blair's government in the Iraq war. And they moved to the left and put his brother in as leader because the British labor movement wanted it. When David Cameron thumped him in the election, they reached the interesting conclusion that they lost because they'd hadn't moved far left enough, so they went out and practically got a guy off the street to be leader of the British Labour Party, who I saw in the press today said that he was really a British citizen and had real British (inaudible).
"But that's what that is reflective of - the same thing happened in the Greek election - when people feel they've been shafted and they don't expect anything to happen anyway, they just want the maddest person in the room to represent them."
Clinton served as US President from 1992 to 2001, recording the highest end-of-office approval rating of any president since World War II. He worked closely with former Labour Prime Minister Tony Blair, who was elected in 1997 and still maintains a friendship with him to this day.
Corbyn, who was re-elected Labour leader in September after the majority of his own MPs called for him to resign, is a figure who splits opinion. His supporters say he is principled and represents a brand of socialism which was lost under the leadership of Blair, while his critics say he is incompetent and point to his terrible ratings in recent polls.
The Islington North MP was left red-faced earlier this year when his claim that fellow left-winger Bernie Sanders sent him a message of support was dismissed by the US senator. Sanders, who like Corbyn is seen as an anti-establishment figure, failed in his attempt to be the Democrat nomination for the US Presidential election.
Business Insider has contacted Clinton's office for a response.