The European Central Bank was quick to react, arguing that it follows decisions taken by the European Court of Justice — not national courts. However, the German ruling has sparked an unprecedented legal minefield and has led to new questions about the future of the euro zone.
Court rules that European Central Bank’s 2015 bond-buying program could be illegal.
This is the most serious challenge to the EU's legal framework we have yet come across. In the UK, the courts operated under the assumption that conflicts between EU and UK law would always be settled on the basis that EU law is supreme.