Merkel calls shock far-right vote in Thuringia state 'unforgivable'

German Chancellor Angela Merkel on Thursday said it was "unforgivable" that a politician in Thuringia allowed himself to be elected state premier with help from MPs of the far-right AfD, calling for a fresh vote.

The surprise election of Thomas Kemmerich from the liberal Free Democrats (FDP) on Wednesday shattered a political taboo in Germany, where mainstream parties have vowed never to work with the anti-Islam, anti-immigrant AfD.

What happened in Thuringia "is unforgivable and that's why the result must be reversed", Merkel said at a press conference in South Africa, describing Wednesday's drama as "a bad day for democracy".

The aftershocks are being felt in Berlin as well, since local MPs from Merkel's own centre-right CDU party also backed Kemmerich in the third run-off vote for the premiership, putting them on the same side as the AfD.

Merkel's centre-left Social Democratic coalition partners have reacted furiously to the debacle, calling for the CDU to clearly distance itself from the AfD if the national alliance is to survive.

Both parties are meeting for crisis talks in Berlin on Saturday.

Merkel made clear that local CDU lawmakers were not allowed to help Kemmerich cobble together a minority government in the small state of Thuringia, eastern Germany.

"The CDU must not take part in a government led by this premier," she told reporters.

Merkel said the actions of her local allies in Thuringia "broke with the values and convictions of the CDU".

"We must now do everything we can to make clear that this can in no way be reconciled with what the CDU does and thinks, and that's what we will work on in the coming days," she added.