The far-right Alternative for Germany (AfD) is “very, very close” to taking power, its deputy parliamentary leader has told the BBC, after a historic victory in elections for the eastern state of Saxony-Anhalt.

Sunday’s preliminary results show it fell three seats short of an outright majority, with 43.8% of the vote. It is now seeking support from other parties or individuals in order to govern.

While most German political parties refuse to work with the AfD, Beatrix von Storch called for its opponents to enter talks and said: “You cannot say I do not accept the vote of the people”.

Germany’s Chancellor Friedrich Merz said his party, the conservative CDU – which won 17.2% of the vote, according to the preliminary results – was “deeply shocked” by the outcome.

He said it was not possible to return to “business as usual”, adding that the country needed “profound reforms” and the CDU needed to “reach people at an emotional level.

“This election result is a seismic result not just in the country but also in my own political party and I take that very seriously,” he said.

No far-right party has controlled a German state since World War Two, and governing at state level would mean powers over policing and local education.

Von Storch said the state’s results “were on the table and now democrats have to talk to [one] another. This is what democracy demands”.

She added that if parties refused to work with the AfD, “then we might end up in severe chaos and maybe we have a new election”.

Her comments were echoed by AfD’s leader in Saxony-Anhalt, Ulrich Siegmund, who told a news conference on Monday that the party had won a “clear mandate to govern”.

Saxony-Anhalt has a small population of 2.1 million and the AfD in the state is assessed by domestic intelligence as “right-wing extremist”, a classification rejected by Siegmund, 35.

The party’s plans for Saxony-Anhalt, which include segregating child refugees into special classes and setting up a task-force to help detain and deport migrants who no longer have the right to be in the state, are highly controversial within Germany.

Siegmund said discussions with other parties were initiated on Sunday night and could potentially take days or weeks to conclude.

“We reach out to everybody first, we will have consultations and then we’ll see whether [there are] individual parliamentary groups or MPs who would be willing to help us,” he added.

The AfD is currently heading for 39 seats in the 83-seat state parliament instead of the 42 needed for an outright majority, although the result has not yet been finalised.

Von Storch told the BBC the AfD was talking to individuals within the CDU group – the largest party in both the state’s outgoing coalition and Germany’s government – because they were “very, very unhappy with their own party”.