The general election is to be held on 6 May. Key questions about how an election works are answered below.
Questions about voting
Questions about standing
Questions about the system
Questions about BBC coverage
WHEN IS THE ELECTION?
6 May. Votes are traditionally held on Thursday, but do not have to be. Elections cannot be held on weekends or public holidays.
WHAT ARE WE VOTING FOR?
The general election will decide which party (or coalition of parties) forms the next government. There will be 650 seats in the UK Parliament's House of Commons up for grabs - up from the current 646 because of
constituency boundary changes.
WHO CAN VOTE?
You must be registered to vote, be at least 18-years-old on polling day, be British or be a Commonwealth or Republic of Ireland citizen living in the UK.
WHO IS BANNED FROM VOTING?
The following are barred from voting in general elections: members of the House of Lords; convicted prisoners; anybody found guilty of election corruption within the last five years; people who are subject to any "legal incapacity" which impairs their judgement.
HOW DO I REGISTER TO VOTE?
Most people register between September and November every year when the local electoral registration office delivers a registration form to your home. This is known as the "annual canvass". However, you can also register throughout the year as the register is updated every month between December and September. This is useful if you move home and need to register at your new address. You can check whether you are on the electoral roll by contacting the electoral services department at your local council. Their contact details are listed on the Electoral Commission's special website.
HOW DO I VOTE?
Those registered to vote should be sent a polling card about a week before the election, naming your polling station. You should take the card with you to vote, although it is not compulsory. No other form of identification is required, except in Northern Ireland.
CAN I VOTE BY POST?
Yes. The general election is not an all-postal vote, but you can ask for a postal vote from the electoral services department at your local council - whom you should also contact if your polling card fails to arrive. If you apply for a postal vote and then decide you would like to vote in person after all, you must take the whole of your postal voting package to the polling station in order to vote. If you have applied to vote by post, you cannot vote in person at the polling station. However, on election day you can return your postal vote to the polling station, before 10pm, or to the returning officer at your local council (before they close), if you do not want to post it or it is too late to post it.
WHAT ABOUT PROXY VOTES?
You can only apply for a long-term proxy vote if you have a specific reason such as a disability or being overseas. To vote by proxy for just one election, you must have a reason, for example you will be on holiday or away due to work. If you are suddenly incapacitated or taken ill, you can apply to vote by proxy for medical reasons up until 5pm on polling day.
IF I LIVE OVERSEAS, CAN I STILL VOTE?
Yes. You can register as an overseas voter if you are a British citizen and have been on a UK electoral register at any time within the past 15 years. To do so, you must be registered in the local authority area where you wish to vote. The deadline for registration is 1700 on Tuesday 20 April.
WHAT HELP IS THERE FOR DISABLED VOTERS?
To help blind and partially sighted voters, there has to be a "tactile device" in each polling station and there are rules on the size of print on ballot papers. The vast majority of poling stations are now more accessible for wheelchair users. Proxy ballots are allowed for those unable to vote because of disability. A doctor's note is required if the person with disabilities is applying for an indefinite proxy vote.
WHAT HAPPENS IF A VOTER IS ILLITERATE
There is no literacy qualification for voting: anyone who is illiterate can ask the polling officer at the polling station to mark their ballot, or take a companion to help them.
WHAT IS ON THE BALLOT PAPER?
You will be given an officially marked ballot paper listing all the candidates in alphabetical order of surname, with the description of their party, if they have one. You place an X in the box beside your one chosen candidate.
IS VOTING COMPULSORY?
No, people cannot be forced to vote, nor is registration itself compulsory.
IS MY VOTE SECRET?
The ballot papers contains a serial number: it is possible, but illegal, to trace all the votes to the people who cast them. The number is there to stop electoral fraud.
HOW CAN I BECOME A CANDIDATE?
To be a candidate, you need to have a nomination form signed by 10 voters from that constituency. The papers must be returned along with a £500 deposit. Candidates do not need to be a member of a political party. The main parties have their own selection methods, usually involving central lists of candidates and votes of local members.
WHO CAN STAND AS A CANDIDATE?
Candidates must be aged 18 or above and be British, Commonwealth or Republic of Ireland citizen. Those banned for standing in general elections are: bankrupts; civil servants; police officers; armed forces personnel; government-nominated directors of commercial companies; judges; members of parliament in non-Commonwealth nations; those convicted of electoral malpractice; members of the House of Lords.
HOW CAN I SET UP A POLITICAL PARTY?
All political parties have to be registered with the Electoral Commission, a process which costs £150. The commission will need the names of three party officials and details of the party's financial schemes. It can decide to refuse to register a party if its name is confusingly similar to another party's or if the name is offensive in some way.
CAN CANDIDATES SPEND AS MUCH AS THEY WANT ON CAMPAIGNING?
No, there are strict limits on what is spent once nominations close on 19 April. Each candidate has to account for their election expenses after the poll. Candidates in rural (county council) areas can spend up to £7,150 plus 7p per elector. Those standing in urban (borough council) areas can spend £7,150 plus 5p per voter.
HOW MUCH CAN THE PARTIES SPEND?
Registered parties are restricted in their spending for the 365 days before the election. Parties can spend up to £30,000 for each seat they contest - which adds up to £19.5m if they fight every constituency.
WHERE DOES THEIR MONEY COME FROM?
Political parties and candidates raise funds in a variety of ways from subscriptions to local fetes and dinners. There are strict rules on donations: those of more than £500 to a party or £50 to a candidate have to be from permissible donors - effectively banning overseas gifts. All donations of more than £7,500 to a party, or £1,500 to a local branch, have to be publicly declared.
IS THERE ANYTHING TO PREVENT THIRD PARTIES SPENDING EXTRA MONEY BACKING POLITICAL PARTIES' CAMPAIGNS?
Yes, people or groups campaigning on behalf of one or more political parties or candidates who advocate a particular policy, face limits too. They can spend up to £10,000 in England and £5,000 in each of Scotland, Wales and Northern Ireland. The groups also must pass the same tests which apply to political donors.
WHO ORGANISES THE ELECTION?
The top civil servant of the local council is the returning officer for each constituency, with the day-to-day running of the poll left to the head of the council's electoral services department.
HOW MUCH DOES IT COST TO RUN AN ELECTION?
The last general election, in 2005, cost more than £80m to organise, according to the Ministry of Justice, which oversees the event.
WHY ARE ELECTIONS HELD ON THURSDAYS?
They do not have to be - it is just a convention. One theory about its origins is that people were not paid until Fridays and so holding polls on Thursdays ensured they were not too drunk to vote. The Electoral Commission has recommended trials of weekend voting as a way of improving turnout.
HOW DOES THE VOTING SYSTEM WORK?
The UK uses a first-past-the-post system. To become an MP, a candidate simply has to win more votes than any rival in their constituency, not a majority of votes cast.
HOW CAN I FIND OUT WHAT A CANDIDATE OR PARTY BELIEVES?
Each party should publish an election manifesto which is available from them or can be bought in the shops. Candidates will campaign locally and are entitled to one free mailing of an election leaflet to voters in their constituency.
HOW MANY MPs DOES EACH PARTY HAVE?
Labour, the governing party, accounts for 346 MPs. The Conservatives have 193, the Liberal Democratss 63 and the Democratic Unionist Party eight. Eight MPs are independents, while one is "independent Labour" and another is "independent Conservative". The Scottish National Party has seven MPs, Sinn Fein five, Plaid Cymru three and the Social Democratic and Labour Party three. Respect and the Ulster Unionist Party have one apiece. Meanwhile, the Speaker and his deputies account for another four MPs.
HOW DOES A PARTY LEADER BECOME PM?
The day after a general election, if any party wins a majority of Commons seats, the Queen invites its leader to become prime minister and to form the government. If he or she says yes, they become prime minister immediately. Their predecessor then moves out of Downing Street.
WHAT HAPPENS IF THE PRIME MINISTER LOSES HIS SEAT?
His party would offer up a candidate to take over temporarily as a caretaker leader/prime minister. The Queen would then call the potential prime minister to Buckingham Palace to ask him whether he would form a government. The governing party would then hold a leadership election.
WHAT IF NO PARTY WINS A COMMONS MAJORITY?
The situation becomes more complex if no party has a majority of MPs. The largest single party could try to form a minority government, but this would involve difficulties with getting business done and may prove unworkable. It, or other parties, could try to form a coalition, with the result that their combined MPs provide a Commons majority. Or it could reach an informal agreement with another party not to vote against it when a "no-confidence" motion is tabled by the opposition, enabling it to become a sustainable government.
ARE THERE RULES FOR THE BBC'S COVERAGE?
Every part of the BBC has to follow
set down by the corporation's governors. They include advice on the "appropriate" level of coverage to give the main parties and how to reflect the smaller ones such as the SNP, Plaid Cymru and UKIP, the Greens and the BNP.
On the election website, we
profile parties and their leaders
if they are fielding candidates in at least one sixth of seats in one or more nations of the UK, and/ or are represented in the House of Commons during the last Parliament, and/ or are represented in one of the devolved institutions (Scottish Parliament, Welsh Assembly, Northern Ireland Assembly), and/ or are represented in the European Parliament.
A party is included in the
Where They Stand policy guide
if fielding candidates in at least one sixth of seats in one or more nations of the UK.
Any party standing at this election can be included on
HOW DO THE SEAT CALCULATOR, SWINGOMETER AND POLL TRACKER WORK?
Details of how our
work can be seen on the relevant pages below each application.
guide to the opinion polls has its own
how it works page
WHY DOES THE POSTCODE SEARCH NOT GIVE THE RESULT I EXPECT?
We are aware of a small number of discrepancies where a postcode search result on our election website - which is based on latest available data supplied to us by Ordnance Survey - returns a different constituency to the one given on polling cards sent to an address at the same postcode.
Normally the constituencies concerned are next to each other, and it appears these discrepancies occur when postcodes are on the border between the two constituencies.
We would advise people affected to follow the information on their polling card in terms of the constituency they are in and the polling place to be used on 6 May.
If you have a question you want answered that is not on the list, then feel free to get in touch using the form below.
The BBC may edit your comments and not all emails will be published. Your comments may be published on any BBC media worldwide.