Sen. Bernie Sanders congratulated Jeremy Corbyn and the Labour Party he leads for what’s being called one of the most stunning upsets in U.K. political history. 

“I am delighted to see Labour do so well,” said Sanders, who campaigned for Corbyn in the days before the election. “All over the world, people are rising up against austerity and massive levels of income and wealth inequality. People in the U.K., the U.S. and elsewhere want governments that represent all the people, not just the 1 percent.”

Though Theresa May’s Conservative Party will still be the largest in Parliament, and she has vowed to continue on as prime minister, conservatives had hoped to gain seats and bolster their majority. Instead, they lost seats and the majority, and will be forced to form a coalition government with a smaller party.

While Corbyn would have likely faced removal as party leader if results had been as dire for Labour as originally predicted, presiding over Thursday’s gains will probably cement his status at the head of the party for some time.

Sanders has a lot in common with Corbyn. Both were seen as long-time fringe figures by the political establishment, with both supporting socialist policies for decades while Labour and Democrats moved to the right. Just as Corbyn shocked the UK by first winning the election to lead Labour, and then by gaining a large number of seats Thursday, Sanders ran a surprisingly strong campaign against Hillary Clinton, who was backed by establishment Democrats, for the party’s presidential nomination last year.