Election 2015: Who can build a majority?
This is the closest general election in decades - here is everything you need to know about what happens if there's no clear winner in Thursday's election.
How many MPs do you need to form a majority?
A majority is where your party has more MPs than all the other parties put together. If every MP takes up their seat, the finishing line for a majority is 326. However, because Sinn Fein do not send their MPs to parliament the actual number required for a majority is 323. That would be enough for a government to vote through new laws without being defeated by their opponents.
Will the leader of the party with the most MPs become prime minister?
Not necessarily. The prime minister will be whoever can control a majority in the House of Commons. It is possible for the party that came second to form a government with the help of other parties.
What is a hung Parliament?
When no single party can get enough MPs to form a majority on its own the Parliament is said to be "hung".
Who gets the first go at putting together a deal?
David Cameron will stay on as prime minister while he tries to put a majority together.
If it becomes clear that he can't and Ed Miliband can, then he will be expected to resign. Mr Miliband will then become the prime minister.
But the Labour leader does not have to wait until Mr Cameron has exhausted all his options before he starts trying to put a deal of his own together. He can hold talks with potential partners at the same time as Mr Cameron. They may even be talking to the same people.
How long will it take?
There is no official time limit. It took five days to put the coalition together in 2010 but is expected to take a lot longer this time.
Negotiations can't go on indefinitely, surely?
The first deadline is Monday 18 May, when the new Parliament meets for the first time. David Cameron has until this date to put together a deal to keep himself in power or resign, according to official guidance issued by the Cabinet Office.
But Mr Cameron must be clear that Ed Miliband can form a government and he can't.
What if it is still not clear a new government can be formed?
The only test for whether a government can be formed is whether it has the confidence of the House of Commons.
In other words, can it assemble the votes it needs to get its programme of proposed new laws passed in the Queen's Speech? The date of the Queen's Speech is Wednesday, 27 May.
David Cameron may opt to remain in power and gamble on getting enough votes from other parties to get his programme passed. If he has already resigned and handed over to Ed Miliband, this will be the key test of whether the Labour leader can form a government.
What role does the Queen play?
The leader of the party that can tell the Queen they have a workable Commons majority is the one Her Majesty will authorise to form a government.
By convention, the Queen does not get involved in party politics, so there are no circumstances in which she would choose the prime minister.
There have been suggestions that she may not deliver the Queen's Speech in person if there's a question mark over whether it will get voted through.
Who runs the country while negotiations are taking place?
Britain's top civil servant, Cabinet Secretary Sir Jeremy Heywood, has said he believes the prime minister should remain in office until a power-sharing deal is clinched. This happened in 2010 when Gordon Brown remained in Number 10 until the Lib Dems and Conservatives put together a coalition despite press accusations he was "squatting".
What about ministers who lose their seats?
Sir Jeremy has said he believes they should remain part of a "caretaker" government until a new administration takes power. The top priority, he told a committee of MPs, was to keep the wheels of government turning because there were constant decisions to be made.
What role would the civil service play?
Civil servants are expected to remain impartial and offer administrative support to all sides taking part in power-sharing talks.
What is a coalition?
A coalition is when two or more parties join forces to govern as a single unit. The junior partners are given ministerial jobs and a joint programme for government is set out.
Forming a coalition depends on four factors:
- Whether the potential coalition partners have enough MPs between them to command a workable majority.
- Whether the biggest party wants to do it or would prefer to try governing alone as a minority government.
- Whether the potential partners can convince their respective parties that it is a good idea.
- Whether they can find enough common ground on policy - the junior partners will inevitably have to ditch some of their policies but they will insist on keeping others.
What are 'red lines'?
These are the policies potential junior partners in a coalition will insist on keeping.
Before the election the SNP said it would insist on Britain's Trident nuclear weapons being scrapped and a halt to public spending cuts and UKIP said they want a referendum on Britain's membership of the EU this year.
The Liberal Democrats set out five "red lines": A £12,500 personal tax-free allowance, increased spending on education, a "stability" budget within the first 50 days, an end to public sector pay restraint and more money for the NHS.
What is a minority government?
If Labour or the Conservatives are unable to put together a coalition or decide to go it alone, they can form a minority government, filling all the ministerial positions themselves.
It means they won't be able to get all of their policies through but may have to make fewer concessions to smaller parties.
Ed Miliband has said he would rather form a minority government than enter into a coalition with the SNP, if he does not get a majority.
Here is a full breakdown of where all the parties stand on post-election deals with each other.
How many MPs would a minority government need for it to be a feasible option?
A party could fall well short of an outright majority and still run a minority government. Sinn Fein don't take up their seats in the Commons so if they return five MPs again, the overall majority target falls to 323.
A new Conservative or Labour government would also face a fractured opposition. For it to be defeated, the Lib Dems, SNP, UKIP, Plaid Cymru, the Greens and the DUP would all have to gang up together to vote against it. This would not happen very much in practice. It is not enough for the losing parties to have more MPs than the "winner". They have to be able to form a coherent alternative.
How stable would a minority government be?
Britain has had minority governments before. They have rarely lasted long but that was before the Fixed-Term Parliament Act, which may make it easier for a minority government to stay in power.
The SNP governed in Scotland as a minority government between 2007 and 2011. It means the government has to form alliances and deals with smaller parties to secure their support in Commons votes - but they can achieve some stability by entering into a "confidence and supply" agreement with another party.
What is a "confidence and supply" agreement?
When a smaller party, such as the SNP or the Lib Dems, agrees to support a larger party, such as Labour or the Conservatives, in key Commons votes to keep it in power is called "confidence and supply".
The smaller party's MPs are unlikely to be given ministerial jobs but they will have some say over the policies of the new government.
It is a looser arrangement than a full coalition. Labour leader Ed Miliband has ruled out a confidence and supply deal with the SNP.
What does the "confidence" bit mean?
Governments usually fall when they are defeated in the Commons on a "confidence" vote. Under a "confidence and supply" arrangement, the junior coalition partner would agree to support the government if the opposition attempted to topple it by tabling a "confidence" motion.
What does the "supply" bit mean?
This is a reference to finance bills - legislation to supply the minority government with the money it needs to enact its policies. The junior coalition partner would vote with the government to ensure they got their Budgets through the Commons.
What about a "vote-by-vote" deal?
This is a looser arrangement than "confidence and supply". It means the minority government could count on the support of a smaller party in some votes but not in others.
Before the election the SNP did talk about supporting Labour on a "vote-by-vote" basis.
This could, in theory, give it the freedom to vote against spending cuts in an emergency Labour Budget without toppling Ed Miliband from power.
This would not have been the case in the past, when votes on finance bills were automatically seen as "confidence" issues. But the rules have changed since 2010.
Will there be another election?
In the past, when minority governments have been formed at Westminster, the prime minister has held another election at the earliest opportunity to try and gain a working majority. Or the opposition has forced another election by tabling a "confidence" motion.
The first of these options will not be possible this time and the second one will be more difficult.
The Fixed-Term Parliament Act - passed by the Lib Dems and Conservatives to make their coalition less likely to collapse - has set the date of the next election in May 2020.
An election can only be held before that date if:
- Two-thirds of MPs vote for it. In practice, that would mean it would need to be supported by both Labour and the Conservatives
- A motion of "no confidence" in the government is passed by a simple majority of MPs. An election must then be called within 14 days unless a new government can win another confidence vote before that period is up
Previously, if a government could not get a Budget or a Queen's Speech through the Commons, it was considered an effective vote of "no confidence".
But under the Fixed Term Parliament Act, the only confidence motion MPs can vote on is this: "That this House has no confidence in Her Majesty's government". This makes it more difficult to for a government to fall.
Is there any way round this?
We are in uncharted waters here. Britain does not have a written constitution and experts are divided over what may happen if no one can form a government.
Here are some alternative scenarios:
- If a "no confidence" motion is passed is in the Commons, the prime minister could hand the party leadership to a colleague, who could have another try at winning a confidence vote before the 14 day grace period is up.
- If the prime minister wanted to trigger an early election, he could table a "no confidence" motion in his own government and order his MPs to abstain but, as YouGov polling expert Peter Kellner has pointed out, this would risk the ridicule of MPs and the public.
- The prime minister could resign, after being defeated on the Queen's Speech for example, and hand power to the leader of the opposition, who would attempt to govern until 2020. This raises the prospect of a change of governing party without an election - something that has never happened in Britain.
So the prime minister may have to carry on even though he can't get key legislation passed?
It's possible. If a minority government is defeated on its Budget, the prime minister would normally follow this up with a confidence vote to trigger a new election.
But if the main opposition party does not want another election, because it thinks it could not win, then it could refuse to table a "no confidence" motion.
In that scenario, the prime minister could theoretically remain in Number 10, despite being defeated on a key part of his economic programme.