The European Union is a completely different system to the way we practise democracy as a nation in the UK. New legislation is largely proposed by the bureaucrats - the European Commission - not by politicians, although the Council of Ministers (representatives of national governments) can tell the bureaucrats what areas to investigate. So the bureaucrats have a lot more power than in the UK, where the convention is civil servants merely carry out the will of elected ministers.
At every level there's a lot of horsetrading that goes on that is quite remote from ordinary citizens - which makes the EU quite undemocratic and enables bureaucrats and national governments to get away with stuff (like throwing out the then governments of Italy and Greece) without bothering to ask the voters.
The European Parliament can in some limited circumstances throw out certain legislation, or amend it. But it works in blocs of parties that share interests but can be very different - that's why Cameron took the Tories out of the bloc they had been in until he became PM. But he was thought to have behaved stupidly as it meant the Tories were not part of a particularly powerful alliance any more.
With the Council of Ministers, to some extent representatives from each national government fight their own corner - but they can also get away with stuff that their own electorate would not necessarily back, particularly in Britain where scrutiny of European politics is quite limited.
European bureaucrats will tell you quite proudly that it's all very democratic because they consult 'stakeholders'. I'm uncomfortable with this - of course governments should consult relevant organisations when considering legislation that affects their areas of operation, but it can all get far too cosy. They are supposed to serve the people, not special interest groups.
And it's the bureaucrats who decide how much weight to give to the different interest groups - I know the General Medical Council protested quite loudly about proposals to extend the right to work anywhere in the EU to doctors, because medical education and health services vary so much - most countries don't have GPs in the way we do (apart from Denmark) for instance. The EU went ahead anyway, so we ended up with a German doctor who had mostly done cosmetic surgery coming over here to do out of hours GP shifts and killing a British patient within his first few hours on our soil. Given that German doctors of his type don't usually deal with morphine. It was the EU that stopped the UK testing the language skills of EU doctors - so potentially Australian GPs who speak English as a first language have to sit a language test, but Spanish doctors don't. Although I think there's been some negotiation there and the GMC is now looking at (or has decided they might have the power to) introduce a language test.
We also have a problem with medical devices and the EU. A device can be approved in one EU country that has a remarkably lax approach, and then it is automatically available in Britain - and tbh our arrangements for licensing and tracking the safety of medical devices are nothing to write home about, but it doesn't help when manufacturers can shop around for an original licence from a country that isn't going to look too carefully.