A German state premier elected on Wednesday with the help of the far-right AfD has said he will stand down to pave the way for fresh elections.
The election of liberal leader Thomas Kemmerich in the eastern state of Thuringia prompted national outrage.
"Resignation is unavoidable," he said. For years Germany's main parties have shunned Alternative for Germany (AfD).
Chancellor Angela Merkel – whose own party backed Mr Kemmerich in the vote – called the election "unforgivable".
The AfD has grown in popularity in recent years but has been condemned for its extreme views on immigration, freedom of speech and the press.
Wednesday's vote was described as a political earthquake as it was the first time the AfD helped form a government in Germany, breaking a consensus among the main parties to never work with extremist parties.
Mr Kemmerich has now announced fresh elections in the state, "to remove the stain of the AfD's support for the office of the premiership".
What happened in Thuringia?
Despite the AfD having broad support in Thuringia, the state election in October was won by the far-left Die Linke. The AfD had just 5% of the vote, barely scraping into the local parliament in the state capital, Erfurt.
But on Wednesday, in the secret vote to pick the leader of the government after Die Linke's leader Bodo Ramelow was ousted from power, Mr Kemmerich beat Mr Ramelow by 45 votes to 44 – thanks to votes from the AfD.
Mr Kemmerich also got votes from local MPs in his own liberal Free Democrats (FDP) and Mrs Merkel's Christian Democrat (CDU) prompting outrage from critics, who said the two centre-right parties had apparently made a pact with the far right.
Mr Kemmerich insisted there had been no co-operation with the far right and accused the AfD of carrying out a "perfidious trick to harm democracy".
However, there are now suggestions the FDP and AfD had discussed a pact in Thuringia before.
A letter sent by AfD's Thuringia leader to Mr Kemmerich on 1 November has gone viral on Twitter, in which the regional AfD leader offered his party's support – either to form a technocratic government or a minority FDP-led government. It would break the long-standing red-red-green ruling coalition in Thuringia, he said.
The letter, first reported by regional broadcaster MDR at the time, shows that the AfD was seeking a deal long before Wednesday's political shock.
What was the reaction?
There were immediate calls for Mr Kemmerich to resign. Speaking on a visit to South Africa, Chancellor Merkel said the Thuringia vote had to be reversed.
"It was a bad day for democracy, a day that broke with the long and proud tradition of the CDU's values. This is in no way in line with what the CDU thinks, how we have acted throughout our party's existence," she said.
CDU leader Annegret Kramp-Karrenbauer also said Mr Kemmerich should stand down, and her party's Social Democrat coalition partners in Berlin called on the CDU to distance themselves from the AfD. Both parties plan to hold crisis talks on Saturday.
Amid the growing pressure, Mr Kemmerich told reporters on Thursday that his FDP had decided to request the dissolution of the state parliament.
FDP leader Christian Lindner had travelled to Erfurt on Thursday for talks with Mr Kemmerich ahead of the party's statement. After the resignation he called for a vote of confidence in the party's national leadership.
Some have compared the AfD's surprise move to the Nazis' rise to power and there were protests in several German cities after the election.
In 1930 a Nazi entered the Thuringia government, the party's first big breakthrough in the Weimar Republic, culminating in Adolf Hitler's appointment as chancellor in 1933.
The Thuringia AfD is led by Björn Höcke, one of the AfD's most controversial figures.
He sparked an outcry when he condemned the decision to place the Holocaust memorial in the heart of Berlin, describing it as a "memorial of shame".
What is the AfD?
The anti-immigration and anti-Islam AfD has MPs in all 16 of Germany's state parliaments.
Nationally the AfD has 89 seats in the lower house oRead More – Source