UK, Ireland and Denmark able to opt out of refugee quotas

The UK, Ireland and Denmark did not join the EU asylum scheme, which was ruled lawful by the European Commission.

The UK, Denmark and Ireland benefit from various negotiated opt outs that themselves vary in relation to the measure involved and the terms for each of them. Additionally, the UK invented the principle of mutual recognition that basically implies there is trust on the part of the EU that its member states will comply with EU law without having to put it immediately into force in national law. In effect this means the UK, Ireland and Denmark "opt in" as and when to certain measures, often once they have considered them in more detail. The benefit of such negotiated provisions, as opposed to what Hungary is doing, mean they do not attract legal warnings and the issue of fines from the EU for doing so.

Opt outs and mutual recognition were themselves a bit of a response to the enhanced co-operation required by the enhanced co-operation on a number of previously sovereign matters under the Amsterdam Treaty. This was also around the time that the EU was expanded to include the former Eastern European states.

Those states are themselves subject to more strict provisions in order to get their systems EU compliant, e.g. in the field of human rights. Hungary has caused quite a lot of concern and received numerous warnings from the EU for breaches of EU law in this regard e.g. on how it has reformed its own constitution, interfered with independence of the judiciary and elections, and so on. Probably due to the Fidensz Party which seems to be locked into unilateral power there for the time being.

Hope that helps!

I think its seen as unavoidable when there are so many different nations involved. All opt outs are negotiated after months of hard discussions under terms which all agree, as majority voting is only possible on minor issues.

In reality, contrary to what most people think, the EU is rather adept at being flexible towards member states. Particularly Britain and Germany, which are big payers and also very good at compliance.

Germany for instance has long had a rule of its own invention that it recognises its own power not to adopt European legislation when it gives its citizens less rights than under the German constitution, which the EU has long since tolerated. (obviously with Germany currently playing the role of the saint of Europe, this doesn't cause any problems, but if its previous history were repeated then it would so do). It is often raised in relation to human or fundamental rights, but few comparisons were made at EU level with UK plans to change their adoption of human rights laws from the EU to something very similar.