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.

As Germany heads to parliamentary polls on Sunday (February 23), the spotlight will be firmly placed on the divisive far-right party, the Alternative for Germany (AfD) and its leader, Alice Weidel.