UK and the EU: Sovereignty and laws
Stats and facts
Britain is a parliamentary democracy. That means we all get to choose the parliaments that make decisions on our behalf at Westminster.
And between elections, those parliaments are sovereign. They call the shots. But in 1972, the UK Parliament decided to give up some of that sovereignty.
It chose to pool some power with other countries in what was then called the European Community. And that means that on some issues, it is the EU institutions in Brussels and not MPs in Westminster who have the final say.
There is disagreement over how many of the laws that govern our lives originate in the European Union. Some of those campaigning to remain in the EU claim that only 13% of laws passed by Parliament implement the UK's obligations under EU law.
This figure ignores the many EU regulations that are automatically binding on the UK and do not pass through Parliament.
Some of those campaigning to leave the EU claim that 65% of UK law is EU-influenced. This figure does include EU regulations but also some which have little impact on the UK, such as those affecting olive oil production.
What does the EU do?
The European Union makes law on a wide range of issues, including common trade rules, subsidies for farming and fisheries, environmental regulations, transport deals, and energy co-operation. That is by no means a complete list.
Although Parliament has ceded some sovereignty to the EU over these and other issues, the UK does still have a say. The government has the power to vote against - or sometimes even veto - proposals in the Council of Ministers.
Britain's 73 MEPs can support or oppose measures in the European Parliament. But once an EU law is agreed, the UK must abide by it or face censure from the judges at the European Court of Justice in Luxembourg, who make sure that no-one is breaking EU rules.
..and what doesn't it do?
Obviously, the EU does not get involved in all legislation.
Parliament retains control over the fundamental decisions: how much of our income is directly taxed, how much of that money is spent on welfare, health and education, how our streets and borders are policed, when and where our armed forces go to war, what our foreign policy is towards the rest of the world, and so on.
And if the UK does co-operate with the EU on any of these issues, it is voluntary and the government can either veto a proposal or choose not to take part.
The UK has opted out of some EU laws and agreements, including economic and monetary union (the euro), the border-free Schengen zone, the charter of fundamental rights, and some security and justice issues.
And of course Parliament could still, at any time, even without a referendum, decide to opt out of the EU entirely by repealing the 1972 European Communities Act. In this way, Parliament remains theoretically sovereign.
The argument for leaving the EU:
Leaving the EU would restore parliamentary sovereignty, returning power from Brussels to Westminster so that the decisions that affect our lives are made by politicians who we can hold to account by kicking them out at a general election.
The argument for staying in the EU:
The benefits of sharing some power within the EU outweigh the negatives, allowing the UK to co-operate with other countries in our national and economic interest, in an era when trade, people and information are less and less constrained by national borders.