The UK's EU referendum: All you need to know

What is happening?

A referendum is being held on Thursday, 23 June to decide whether Britain should leave or remain in the European Union. This article is designed to be an easy-to-understand guide - if you have any questions you can send them in using this link. We'll be answering a selection at the bottom of the page.

What is a referendum?
A referendum is basically a vote in which everyone (or nearly everyone) of voting age can take part, normally giving a "Yes" or "No" answer to a question. Whichever side gets more than half of all votes cast is considered to have won.

Why is a referendum being held?
Prime Minister David Cameron promised to hold one if he won the 2015 general election, in response to growing calls from his own Conservative MPs and the UK Independence Party (UKIP), who argued that Britain had not had a say since 1975, when it voted to stay in the EU in a referendum. The EU has changed a lot since then, gaining more control over our daily lives, they argued. Mr Cameron said: "It is time for the British people to have their say. It is time to settle this European question in British politics."

What is the European Union?
The European Union - often known as the EU - is an economic and political partnership involving 28 European countries (click here if you want to see the full list). It began after World War Two to foster economic co-operation, with the idea that countries which trade together are more likely to avoid going to war with each other. It has since grown to become a "single market" allowing goods and people to move around, basically as if the member states were one country. It has its own currency, the euro, which is used by 19 of the member countries, its own parliament and it now sets rules in a wide range of areas - including on the environment, transport, consumer rights and even things like mobile phone charges. Click here for a beginners guide to how the EU works.

What will the referendum question be?
"Should the United Kingdom remain a member of the European Union or leave the European Union?" Read more: Does the wording of a referendum question matter?

What does Brexit mean?
It is a word that has become used as a shorthand way of saying the UK leaving the EU - merging the words Britain and exit to get Brexit, in a same way as a Greek exit from the EU was dubbed Grexit in the past.

Who will be able to vote?
British, Irish and Commonwealth citizens over 18 who are resident in the UK, along with UK nationals living abroad who have been on the electoral register in the UK in the past 15 years. Members of the House of Lords and Commonwealth citizens in Gibraltar will also be eligible, unlike in a general election. Citizens from EU countries - apart from Ireland, Malta and Cyprus - will not get a vote.

Didn't David Cameron try and change the rules of the UK's EU membership?
Yes. This was the big news back in January and February as David Cameron sought an agreement with other European Union leaders to change the terms of Britain's membership. He says the deal, which will take effect immediately if the UK votes to remain in the EU, gives Britain "special" status within the 28 nation club, and will help sort out some of the things British people say they don't like about the EU, such as high levels of immigration and giving up the ability to run our own affairs.
Critics say his deal will make little difference and falls well short of what he had promised when he announced his plan for a referendum.

The main points of the deal are:
Child benefit - Migrant workers will still be able to send child benefit payments back to to their home country - Mr Cameron had wanted to end this practice - but the payments will be set at a level reflecting the cost of living in their home country rather than the full UK rate
Migrant welfare payments - Mr Cameron says cutting the amount of benefits low paid workers from other EU nations can claim when they take a job in the UK will remove one of the reasons people come to Britain in such large numbers (critics say it will make little difference). He did not get the blanket ban he wanted. New arrivals will not be able to claim tax credits and other welfare payments straight away - but will gradually gain the right to more benefits the longer they stay, at a rate yet to be decided.
Keeping the pound - Mr Cameron has said Britain will never join the euro. He secured assurances that the eurozone countries will not discriminate against Britain for having a different currency. Any British money spent on bailing out eurozone nations that get into trouble will also be reimbursed.
Protection for the City of London - Safeguards for Britain's large financial services industry to prevent eurozone regulations being imposed on it
Running its own affairs - For the first time, there will be a clear commitment that Britain is not part of a move towards "ever closer union" with other EU member states - one of the core principles of the EU. This will be incorporated in an EU treaty change. Mr Cameron also secured a "red card" system for national parliaments making it easier for governments to band together to block unwanted legislation. If 55% of national EU parliaments object to a piece of EU legislation it will be rethought. Critics say it is not clear if this would ever be used in practice.

Who wants the UK to leave the EU?
The British public are fairly evenly split, according to the latest opinion polls. The UK Independence Party, which won the last European elections, and received nearly four million votes - 13% of those cast - in May's general election, campaigns for Britain's exit from the EU. About half of Conservative MPs, including five cabinet ministers, several Labour MPs and the DUP are also in favour of leaving.

Why do they want the UK to leave?
They believe Britain is being held back by the EU, which they say imposes too many rules on business and charges billions of pounds a year in membership fees for little in return. They also want Britain to take back full control of its borders and reduce the number of people coming here to live and/or work. One of the main principles of EU membership is "free movement", which means you don't need to get a visa to go and live in another EU country. They also object to the idea of "ever closer union" and what they see as moves towards the creation of a "United States of Europe".

Who wants the UK to stay in the EU?
Prime Minister David Cameron wants Britain to stay in the EU, now he has got some powers back from it. Sixteen members of his cabinet also back staying in. The Conservative Party has pledged to be neutral in the campaign - but the Labour Party, SNP, Plaid Cymru and the Lib Dems are all in favour of staying in. US president Barack Obama also wants Britain to remain in the EU, as do other EU nations such as France and Germany. As mentioned above, according to polls, the British public seems pretty evenly split on the issue.

Why do they want the UK to stay?
Those campaigning for Britain to stay in the EU say it gets a big boost from membership - it makes selling things to other EU countries easier and, they argue, the flow of immigrants, most of whom are young and keen to work, fuels economic growth and helps pay for public services. They also believe Britain's status in the world would be damaged by leaving and that we are more secure as part of the 28 nation club, rather than going it alone.

So would Britain be better in or out?
It depends which way you look at it - or what you believe is important. Leaving the EU would be a big step - arguably far more important than who wins a general election - but would it set the nation free or condemn it to economic ruin? Here is a rundown of the arguments for and against.

What about businesses?
Big business - with a few exceptions - tends to be in favour of Britain staying in the EU because it makes it easier for them to move money, people and products around the world. BT chairman Sir Mike Rake, a recent CBI president, says there are "no credible alternatives" to staying in the EU. But others disagree, such as Lord Bamford, chairman of JCB, who says an EU exit would allow the UK to negotiate trade deals as our country "rather than being one of 28 nations". Many small and medium-sized firms would welcome a cut in red tape and what they see as petty regulations. The British Chambers of Commerce says 55% of members back staying in a reformed EU.
What are the rules for campaigning?
The Electoral Commission is in charge of making sure it's a fair contest. It has designated lead campaigns for both the "leave" and "remain" sides. The official campaigns - Vote Leave and Britain Stronger in Europe - get access to a grant of up to £600,000, an overall spending limit of £7m, campaign broadcasts, free mailshots and free access to meeting rooms. The Electoral Commission has published a guide to the rules.

So who is leading the rival sides in the campaign?
Britain Stronger in Europe - the main cross-party group campaigning for Britain to remain in the EU is headed by former Marks and Spencer chairman Lord Rose. It is backed by key figures from the Conservative Party, including Prime Minister David Cameron and Chancellor George Osborne, most Labour MPs, including party leader Jeremy Corbyn and Alan Johnson, who is running the Labour In for Britain campaign, the Lib Dems, Plaid Cymru, the Alliance party and the SDLP in Northern Ireland, and the Green Party. Who is funding the campaign: Britain Stronger in Europe has raised £6.88m so far, boosted by two donations totalling £2.3m from the supermarket magnate and Labour peer Lord Sainsbury. Other prominent Remain donors included hedge fund manager David Harding (£750,000), businessman and Travelex founder Lloyd Dorfman (£500,000) and the Tower Limited Partnership (£500,000). Read a Who's Who guide. Who else is campaigning to remain: The SNP is running its own remain campaign in Scotland as it does not want to share a platform with the Conservatives. Several smaller groups have also registered to campaign.
Vote Leave - A cross-party campaign that has the backing of senior Conservatives such as Michael Gove and Boris Johnson plus a handful of Labour MPs, including Gisela Stuart and Graham Stringer, and UKIP's Douglas Carswell and Suzanne Evans, and the DUP in Northern Ireland. Former Tory chancellor Lord Lawson and SDP founder Lord Owen are also involved. It has a string of affiliated groups such as Farmers for Britain, Muslims for Britain and Out and Proud, a gay anti-EU group, aimed at building support in different communities. Who is funding the campaign: Vote Leave has raised £2.78m so far. Its largest supporter is businessman Patrick Barbour, who gave £500,000. Former Conservative Party treasurer Peter Cruddas gave a £350,000 donation and construction mogul Terence Adams handed over £300,000. Read a Who's Who guide. Who else is campaigning to leave: UKIP leader Nigel Farage is not part of Vote Leave. His party is running its own campaign. The Trade Union and Socialist Coalition is also running its own out campaign. Several smaller groups have also registered to campaign.

Source: The UK's EU referendum
Published in BBC, By Brian Wheeler & Alex Hunt
BBC News, A section from UK Politics, June 9, 2016