UK is on the verge of the biggest political solution for decades: to remain a member of the European Union, or to get away from the world's largest single market?
Citizens of the UK across the world will take part in the vote in a referendum to be held on 23 June.
The British economy is the second largest in the EU. Its decision on whether to stay or leave the unit will be of great importance not only for the British people, but also for the global financial markets and the future of the whole of Europe.
1. The campaign will last for 10 weeks
Officially, the campaign began on Friday and will last for a little less than 10 weeks, and will end on 22 June.
2. How much money will it cost the campaign?
There is no set limit on the amount of money that can be spent on the organization of the campaign.
But cost leadership campaigns are expected to be fixed at £ 7 million ($ 10 million). They will have to publish details of any particular loan or donation of more than £ 7500.
Political parties can spend money, contributing to major campaigns or register with as
campaign. In any case, they can only spend up to the limits based on their actual share of the vote in the last general election. This means that Cameron's Conservative Party can spend up to £ 7 million, and the main opposition Labour Party to £ 5.5 million. Labour leader Jeremy Corbin wants Britain to remain in the EU.
Individuals, businesses and other organizations can campaign freely, if they spend less than £ 10 000. If they want to spend more, they must register with the Electoral Commission, and their costs will be limited to the amount of £ 700,000.
3. Who can vote?
Citizens over 18 years old who live in the UK, as well as citizens of Great Britain, who have lived abroad for less than 15 years will have the opportunity to participate in the referendum. Gibraltar Citizens will also be able to vote.
EU citizens residing in the UK - with the exception of the citizens of Ireland, Malta and Cyprus, which have historical links with the United Kingdom - will not have voting rights.
Voters will be asked: "Should the United Kingdom to remain in the European Union, or to leave a single unit?".
4. When will know the outcome?
Counting of votes will begin at 22:00 local time (17:00 Eastern Time) on June 23 and continued throughout the night.
The result will be announced on June 24 announcement will be made in Manchester, in the regional center of the counting of votes in the north-west of England.
5. What will happen then?
If Britain voted for the EU to exit the composition of Prime Minister Cameron will have to formally inform the other European leaders, giving the grounds for challenging a two-year negotiations on the release point.
If the United Kingdom will vote for it to stay, Cameron will have to reform the relations with the EU.