Weidel said voters had delivered a “clear majority” for a coalition with the AfD, which came second, and the winning Christian Democrats (CDU). But CDU leader Friedrich Merz has ruled out a coalition with the far-right party.

The leading candidate, Friedrich Merz, a conservative who has adopted many of the AfD’s hard-line positions on immigration, used his closing statement of the debate to promise his voters that he would never allow the AfD into his government. Under him, he said, the firewall would hold.

Germany's conservatives won the national election on Sunday, while the far-right Alternative for Germany came in second, its best ever result.

Concern is growing over the far-right Alternative for Germany party’s rise ahead of the German election. Its U.S. supporters include Elon Musk and JD Vance.

Trump hailed the result as a "GREAT DAY FOR GERMANY," while the far-right AfD party that Elon Musk has championed made historic gains.

Polls are open across Germany as the world’s third largest economy chooses a new leader to guide it through an era of febrile immigration debates and souring relations with Washington.

Alice Weidel, has vowed to "chase" the country's other parties if her party goes into opposition. The CDU/CSU centre-right bloc is leading according to initial projects, and its leader Friedrich Merz has repeatedly ruled out a coalition with the AfD.