Germany's ruling coalition on Saturday called for new elections in the eastern state of Thuringia as the state prime minister announced resignation after a political outcry.

The out-going state Prime Minister Thomas Kemmerich of the pro-business Free Democratic Party (FDP) was elected to the position three days ago with the support of the right-wing Alternative for Germany (AfD) in a state assembly vote.

The unexpected result shocked Germany's political circle as working with the AfD has been as a red line for German major parties.

Kemmerich announced his resignation officially on Saturday as pressure mounting.

"The election of Thuringia's state premier, only secured the majority with the votes of AfD, is unforgivable," said a joint statement by the ruling parties Christian Democratic Union/Christian Social Union(CDU/CSU) and Social Democratic Party(SPD).

"We rule out forming a (state) government or political majorities with the votes from the AfD," the statement said.

The governing coalition called for a new state prime minister to be elected immediately and, if necessary, a new state parliamentary election to be held.

Thuringia held its local parliamentary election last October and formed a complex political landscape, providing no obvious coalition.

The Left Party won the election, garnering 31 percent of the vote and AfD got 23.4 percent. CDU and SPD took a severe setback securing only 21.8 percent and 8.2 percent respectively.

The Green Party and FDP merely surpassed the threshold to enter the parliament with 5.2 percent and 5 percent.

The Left Party, the SPD and the Greens had intended to run a three-way minority coalition with Bodo Ramelow of the Left Party as state prime minister.

But the plan was foiled after AfD dramatically switched their votes from its own candidate to Kemmerich, who was supported by CDU and FDP.

German Chancellor Angela Merkel said earlier this week that the majority made possible with AfD votes was an "unforgivable occurrence" and hinted that the result needed to be reversed.