Alternative for Germany has won a key German election just days after Sir Keir Starmer urged centre-left leaders in Europe to fend off the threat from "snake oil populists".
The AFD won almost a third of the votes in Thuringia.
The result puts the eurosceptic party nine-points ahead of the centre-right CDU, with left-wing Linke slipping from 31 per cent to just 13.1 per cent.
Results in Saxony will also spark concern for German Chancellor Olaf Scholz.
Populist right have won a key German election in hammer blow to Olaf Scholz
GETTYThe result put the AFD a whisker behind the CDU, with the populist party obtaining 30.6 per cent of the votes.
The CDU, best-known as the party which was led by ex-Chancellor Angela Merkel, is narrowly ahead on 31.9 per cent.
AFD support in both Saxony and Thuringia comes as Scholz SPD slips into single-digits.
Saxony witnessed a rapid rise in AFD support, having received 27.5 per cent of the vote in 2019 after previously struggling to break into the teens.
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Keir Starmer and Olaf ScholzPAThe AFD experienced a similar political climb in Thuringia, emerging in 2014 before building ahead of the 2024 state election.
Despite topping the exit poll in Thuringia, it remains possible for other parties to freeze the AFD out of governing the state.
Thuringia's CDU said: "We will seek talks to explore the possibilities of forming a government.
"The following still applies: There will be no cooperation with the AFD."
AFD supporters in Dresden
REUTERS
However, Alice Weidel, one of the AFD’s national leaders, welcomed the result in eastern region.
After thanking supporters, Weidel said: "For us, it's a historic success."
Results in Germany come just days after Starmer returned from Berlin following his meeting with Scholz.
The Prime Minister addressed the growth of populist parties in Europe during his tour of the German capital.
He said: “I think that the challenge has to be met by democracy and by progressives, and we have to have a joint discussion about what that means across Europe and beyond, which I’m very keen to pursue with progressive parties.
German Chancellor Olaf Scholz Reuters“And ultimately, I think that delivery and honesty is the best way of dealing with the snake oil of populism and nationalism, which is why I set out the tough measures I did yesterday in my speech, but also why I’m absolutely determined that we’re going to deliver on the promises that we’ve made.”
The next federal election in Germany, which is scheduled to take place in September 2025, is expected to result in dozens of SPD MPs being ousted from the Bundestag.
Scholz's party is almost 10-points down compared to his victory in 2021, with the CDU/CSU alliance up by six per cent.
However, the AFD could more than double their MPs as the populist party surges from just 10 per cent to 19 per cent.