Boris Johnson, the UK's new prime minister, has ruled out holding a general election before the 31 October Brexit deadline. However, some MPs say they are willing to trigger one in order to a prevent a possible no-deal Brexit.
Prime Minister Boris Johnson has failed to trigger an early general election. The PM had wanted an election on 15 October, two days before a crucial European Union summit in Brussels.
But Dominic Cummings, the prime minister's new adviser, has reportedly told ministers that MPs have left it too late to force an autumn poll.
So why was Mr Johnson unable to call an election and what are his remaining options?
So have MPs missed their chance?
How are elections usually called?
How could the prime minister hold an early election?
Under the Fixed Term Parliaments Act, a prime minister can no longer call an election on their own. They must have the backing of at least two-thirds of MPs.
A parliament lasts for a maximum of five years, so the next election doesn't have to be held until 2022.
In other words, at least 434 MPs have to give the green light to an early election.
If Boris Johnson wants to call an earlier election, he needs at least 66% of MPs to agree to it.
But on Wednesday Mr Johnson only secured 298 votes.
While elections always carry risk, Mr Johnson might hope an early poll would lead to the Conservatives winning more seats - making it easier to pass new laws and deliver Brexit.
Why did Mr Johnson lose?
However, this scenario seems unlikely as Mr Johnson says he doesn't want a snap election before 31 October.
Many MPs were worried that Mr Johnson would not stick to his pledge to hold the election on 15 October.
Could a prime minister be made to have an election?
A motion, under the Fixed Term Parliaments Act, to call an early election does not specify the day it is to take place.
If Mr Johnson chooses not to call an election, MPs could try to force one. They could potentially do this through a vote of no confidence.
Instead, MPs simply voted on whether they agreed with the statement "that there shall be an early parliamentary general election".
Some MPs believe this could prevent a no-deal Brexit on 31 October - something Mr Johnson has refused to rule out.
Senior Labour figures said they would not vote for an early election while there was a risk the prime minister could move the poll to after 31 October - by which point the UK would have left the European Union.
A no-deal Brexit would see the UK immediately leave the European Union (EU) with no agreement about the "divorce" process.
Had enough MPs supported an early election, the prime minister would then recommend the date of the poll to the Queen.
If a vote of no confidence was called, MPs would have to decide whether they want the current government to continue. For of a vote of no confidence to succeed, a majority of MPs need to support it. This might require some Conservative MPs to vote against their own government.
Once the date is known, Parliament shuts down - or dissolves - 25 working days before election day.
If this passes, the government could stay on for 14 days to try to persuade MPs to change their minds.
At this point politicians stop being MPs and they campaign for re-election, if they choose to stand again.
Other parties might also try to come together to form an alternative government during this period. If this happened, Mr Johnson would be expected to resign and a new prime minister could request a further Brexit delay to prevent a no-deal outcome.
Does the PM have other options to call an early election?
But getting MPs to support an alternative government will not be easy. Would Conservatives unhappy with a no-deal Brexit really prefer Jeremy Corbyn as prime minister?
While the Fixed Term Parliaments Act requires a two-thirds majority to sanction an early election, it's not impossible for a government to get round this requirement.
If nothing is resolved after 14 days, a general election is automatically triggered.
It could be achieved by introducing a very short law that calls for an election and adds "notwithstanding the Fixed Term Parliaments Act".
Traditionally, the election would be held as soon as practically possible.
The advantage of this route, from the government's point of view, is that it would only require a simple majority of MPs to support it (more voting for than against) rather than two-thirds.
Once the date is known, Parliament shuts down - or dissolves - 25 working days before the poll. This allows MPs to campaign for re-election.
It would also allow an election date to be set in stone, which might make some MPs more likely to vote for it - although there's no guarantee the government would win.
How soon could a general election happen?
However, this route would take longer. The proposed law would need to clear the House of Lords, as well as the House of Commons. Given that Parliament is due to prorogue (or shut down) next week, getting the legislation passed would be a race against time.
Even with a successful no confidence motion, it would be extremely tight to organise a general election before 31 October.
There's also a risk that the legislation could be amended - allowing pro-remain MPs to make changes, such as forcing a further Brexit extension.
MPs did not call a confidence vote before Westminster went on its summer break. That means 3 September, when Parliament next sits, is now the earliest opportunity to do so.
High-risk options
Assuming the confidence vote is held and passed the next day, the 14-day period the government has to win back support would expire on 18 September.
There is a third, extremely high-risk option. If the government was absolutely determined to hold an early election it could, in theory, call a vote of no confidence in itself.
If that happens, the prime minister could choose to call the election the next day. That would mean dissolving Parliament on 20 September, signalling the start of the five-week campaign.
If it chose to do this, MPs would have to decide whether they want the current government to continue.
The House of Commons Library told the BBC, that such a scenario would leave Friday 25 October as the earliest possible election day - less than one week before Brexit day.
If such a vote passes, opposition parties would be allowed two weeks to come together to try to form an alternative government. If this happened, Mr Johnson would be expected to resign and a new prime minister could request a further Brexit delay to prevent a no-deal outcome.
To hold an election on a day other than a Thursday would be extremely unusual. In fact, you have to go back to Tuesday 27 October 1931 to find the last time this happened.
But, if nothing is resolved after 14 days, a general election is automatically triggered.
Could the prime minister speed things up?
However, this would be a high stakes strategy, as it completely relies on opposition parties failing to form an alternative government.
A compliant prime minister could speed things up.
Catherine Haddon, from the Institute for Government think tank, says the chances of the government calling such a vote are "extremely unlikely".
Instead of having a 14-day period after losing any no confidence motion, the prime minister could decide to call an election.
"From a political point of view, calling a vote of no confidence in yourself would look mad," she says.
He would still need the votes of at least 66% of MPs, but that would trim two weeks off the election timetable.
But why does the PM want an early election in the first place?
Could the prime minister hold the election after 31 October?
Legally, the next election does not have to happen until 2022 - five years after the last one.
If, on the other hand, the prime minister was determined to leave the EU on 31 October, he could try to delay things.
While calling an early election carries risks, Mr Johnson would aim to win more Conservative seats in an attempt to end the political stalemate and make it easier to Brexit.
"Even if a vote of no confidence was successful, it doesn't guarantee the election will happen before Brexit day," says Catherine Haddon, from the Institute for Government think tank.
That's because the prime minister controls the timetable.
"For example, they could extend the wash-up [the period where some unfinished Parliamentary business is dealt with] before Parliament is dissolved," she says.
By doing this, the election could be pushed into November - by which point the UK would have already left the EU.
Could the prime minister face a legal challenge?
Ultimately, it is in the hands of the prime minster, rather than Parliament, to guarantee an election before Brexit is due to happen.
But that does not mean the prime minister would escape a legal challenge.
Dominic Grieve, a Conservative MP and staunch no-deal opponent, has said it would be "utterly perverse" to try to take the UK out of the EU during what is known as the period of purdah before an election.
Purdah is the pre-election period in which government departments are restricted from making and communicating policy announcements.
Instead, he argues, the prime minister must ask for an extension to the Brexit date in that event, adding: "There is a long-established convention that once an election has been called, no government should take anything other than caretaker decisions."
However, in theory the government does not need to take any decisions in order for us to leave on 31 October - that is the default position in law. Brexiteer MP Iain Duncan Smith puts it: "If we are in an election it makes no difference, we still leave because it is law."
Attorney General Geoffrey Cox, the government's number one lawyer, has reportedly told Mr Johnson the same.
But these are uncharted waters and there may not be an obvious answer.
That is why both sides are convinced that in this situation the case would inevitably end up in the Supreme Court, with the 12 justices asked to decide the country's fate.
