[sofixa]

> I had the impression member states were 100% sovereign within the EU...

~80-90% depending on how you measure.

The judiciary of all countries is technically under the ECJ jurisdiction. People can sue their countries, and local court decisions can be appealed to the European court structure (ECJ/ECHR).

That was in fact one of the Brexit talking points, judiciary independence.

[ectopod]

Just to be clear, the ECHR is not an EU court and brexit Britain is still under its jurisdiction.

https://en.wikipedia.org/wiki/European_Convention_on_Human_R...

[M2Ys4U]

And one cannot appeal a case from the court of a member state to the CJEU. Member states' courts can (in some cases must) refer specific questions of law, but that is not an appeal by any party to the dispute.