As a matter of UK law, Parliament is sovereign. No other body has higher standing. Parliament can make any law it likes. The only thing it can’t do is bind its successors.
When the UK joined the European Community (as it then was), Parliament agreed to accept the supremacy of European law. It did this by making the European Communities Act 1972 (ECA). Parliament considered whether to include a section in the ECA that would stop future Parliaments making laws that breached, or purported to have primacy over, European law, but it decided not to do this. Parliament can’t bind its successors. If a future Parliament wanted to breach European law, it could by (i) relying on the implied repeals rule (if Parliament makes two conflicting laws, the second impliedly repeals the first); or (ii) amending or revoking the ECA. So: even if a prohibition was desirable, it wouldn’t work.
When Parliament made the ECA, it chose to temporarily limit its sovereignty by (i) making a UK statute that allowed every relevant European law to become part of UK law; and (ii) providing that, if there was a conflict between UK and European law, European law would prevail, even if the conflicting UK law was newer. This was a legislative choice. Parliament can still repeal or amend the ECA to remove or loosen these restrictions. The result is that, like German law, UK law still has primacy over European law, and Parliament is still sovereign. These legal facts are often overlooked, but they are the result of R -v- Secretary of State for Transport ex parte Factortame Limited ; Thoburn -v- Sunderland City Council ; and section 18 of the European Union Act 2011.
That doesn’t necessarily mean that, if Parliament repealed or amended the ECA, its actions would be consequence free. If might, for example, breach European law. But Parliament could choose to cause the UK to breach European law, and then defend itself against the consequences of that breach (if any). Alternatively, the UK government could give two years’ written notice to the European Union, and walk away without breaching European law (if it thought that would generate a better result). This isn’t so different to the position a person finds himself in, if he enters into a contract, or agrees to join almost any other type of organisation
The legislative choices recorded in the ECA are not only temporary – they’re also partial:
- There isn’t a European law about everything – far from it;
- When there is a European law, it doesn’t always apply in or to the UK – there’s a partial list in the recent UK / EU deal;
- European law often includes derogations and options, so the UK can chose whether to implement some European laws, and how to implement others; and
- European law is often “minimum harmonising“, so the UK can – and often does – require more from UK businesses than European law would otherwise have required.
It’s also worth remembering that new European law is sometimes based on existing UK law; and that, especially in the financial services regulatory space, the UK often plays a significant role in the development of the policy on which European law is based; and then “holds the pen” so that it controls the drafting as well. Although it’s not always happy to admit it these days, Solvency II is a recent example of almost all of these things. And the UK got many of the things it wanted in this way.
So, Parliament hasn’t given its sovereignty away, and the UK doesn’t need to leave the EU for Parliament to recover what it’s lost.
If had, the next question might be: if there’s a #Brexit, would that be enough to allow Parliament to recover what it’s sovereignty, or at least to free itself from the sovereignty restrictions it has chosen to accept? It depends. For example, if the UK chose the Norwegian option or the Swiss option, Parliament would probably have to make a set of revocable legislative choices that are materially the same as the choices it’s already made. In fact, Parliament is only really likely to be European Union sovereignty restriction free if it turns it back on the European Union altogether. But if it did that, it might still have to make other sovereignty restriction choices, as it entered into a series of trade agreements and bi-lateral treaties with individual European and third countries, and that’s been done, the UK may not be very far away from where it is today.