Germany: What is the 'AfD firewall'?

Since the end of World War II and the Holocaust, there has been a consensus among Germany's main political parties that the far and extreme right must never be allowed in government again. This so-called firewall has also extended to open collaboration with far-right parties in any capacity.

However, the conservative Christian Democrats (CDU) breached what has become known as the "AfD firewall" on Wednesday when party leader Friedrich Merz put forward a motion for strict immigration laws, which passed with the support of the far-right Alternative for Germany (AfD).