A far-right party became the biggest force in a German state parliament for the first time since the second world war, exit polls showed on Sunday, while a new populist force on the left established a firm foothold in the country’s political landscape.

Voters in two closely watched elections in the former communist east made their dissatisfaction with Germany’s mainstream political parties clear, putting the Alternative für Deutschland (AfD) party in the top spot in Thuringia, with 32.8% of the vote, and second place in Saxony, with 30.6%, according to preliminary results.

Alice Weidel, the AfD’s co-leader, said: “It is a historic success for us. It is the first time we have become the strongest force in a state election. It is a requiem for this coalition [in Berlin].”

The 11-year-old AfD clinched its first mayoral and district government posts last year, but has never joined a state government. The remaining, democratic parties have vowed to maintain a “firewall” of opposition to working with the AfD, keeping it out of power.

The results in Saxony and Thuringia proved disastrous for the three ruling parties in Chancellor Olaf Scholz’s centre-left-led federal government, each scoring single-digit percentage shares of the vote in both states one year before Germany holds its next general election.

Although the outcome had been predicted for months, the centrist parties proved unable to reverse the trend and the results sent shockwaves through the political landscape. Turnout in both states was high, at about 74%.

The leftwing but socially conservative Sahra Wagenknecht Alliance (BSW), named after its firebrand leader, found that its calls for higher taxes on the rich, a tougher line on immigration and asylum and an end to military support for Ukraine struck a deep chord in the east.

As no party won an absolute majority, the eight-month-old BSW could prove key in talks on forming a government in both states, as it drew 11.8% in Saxony and 15.8% in Thuringia, according to the provisional results.

Wagenknecht told reporters it was the “first time in the history of the republic” that a party had performed so well in state elections on its first try. “That’s something one can be proud of,” she said.

The conservative opposition Christian Democratic Union party (CDU), which is leading in the national polls, appeared on course to win in Saxony as it did five years ago with about 32%, putting wind in the sails of its national leader, Friedrich Merz, who aims to challenge Scholz in the national election.

In Thuringia, it came in second behind the AfD, with 23.6%, and may be able to hammer out an ideologically awkward ruling alliance with smaller parties, including Wagenknecht’s.

Merz has said the CDU will never work with the extremists, but has moved his party steadily rightward, particularly in its rhetoric on immigration, since Angela Merkel left power in 2021.

Many eastern voters say they are increasingly disillusioned with mainstream politics more than three decades after national reunification, with the lingering impact of structural decline, depopulation and lagging economic performance compounding a sense that they are still second-class citizens.

“The AfD has built up a core base [in the east] that now votes for it out of conviction, not just owing to frustration with the other parties,” said Prof André Brodocz, a political scientist at the University of Erfurt in Thuringia.

The anti-migration, anti-Islam AfD spent the last week of its campaign hammering home the message that the government is “failing” its citizens, while harnessing shock and outrage over the deadly mass stabbing in the western city of Solingen, allegedly by a Syrian rejected asylum seeker.

The party, whose Saxony and Thuringia chapters have been classed as rightwing extremist by security authorities, could still come in first in Brandenburg, the rural state surrounding Berlin, which will vote on 22 September, polls suggest.

Its co-leader in Thuringia, Björn Höcke, has repeatedly used banned Nazi slogans at his rallies and called for an “about-face” in Germany’s culture of Holocaust remembrance and atonement.

His aim was to achieve a blocking minority of one-third of the votes in Thuringia, where the Nazis first won power in a German state government in 1930 before consolidating control in Berlin three years later. Final results due by early Monday will show if he was successful.

At a rally in Erfurt days before the election, Höcke told a cheering crowd that he and the AfD were the only ones standing in the way of the “cartel parties” working to “replace the German people” with a “multicultural society” under a “totalitarian dictatorship”.

Given the fractured results handed back by voters, coalition-building in both states could prove tricky.

The BSW’s rise was described as a “gamechanger” by Brodocz, underlining the rejection of the established political parties while offering frustrated easterners an alternative to the AfD, which many see as too radical.

Wagenknecht, already gearing up for the 2025 federal elections, has suggested that she would drive up the price for joining any coalition, demanding “diplomacy” toward Russia while railing against a recent decision to allow the US to deploy long-range missiles in Germany from 2026.

Scholz’s coalition of the centre-left Social Democrats, the ecologist Greens and the liberal Free Democrats was already on the back foot and each of the parties had reason to dread Sunday’s election night results.

Riven by ideological differences and personal rivalries, the government has stumbled in recent months in realising its main policy initiatives, including kickstarting the moribund economy and getting more electric vehicles on German roads. The Greens’ co-leader, Omid Nouripour, recently described the coalition in Berlin as a “transitional government” in the period after Merkel’s 16 years in power.

On Sunday, Nouripour gave a sobering assessment of the election results, saying the breakthrough for the far right “causes many people very deep concern and fear”.