Despite, or perhaps even because of, a year's worth of promises to the contrary, there will now be a snap general election on 8 June. Why, and indeed how, is it happening?

What will happen during the parliamentary vote?

On Wednesday, after Prime Minister’s Questions, 90 minutes has been set aside for a vote on whether to hold a general election, a provision created by the 2011 Fixed-term Parliaments Act that has never been exercised before.

There is no protocol. A spokesperson for the Prime Minister has confirmed that she will be there, but has not gone so far as to indicate whether or not she will address the house.

When does Parliament break up and the campaign begin?

Parliament will be officially prorogued on Wednesday 3 May. There will be local council elections the following day. The campaign will officially begin that day.

Will there be TV debates between the party leaders?

Probably not. TV debates are certainly not party of any constitutional or legal requirement. The terms on which they take place have in the past been brutally fought over by broadcasters, politicians and the Electoral Commission. Theresa May has already suggested she will not take part in any TV debates, just as David Cameron did in 2015. Mr Cameron was fiercely criticised for “bottling” those debates, then went on to win an unexpected overall majority. Theresa May has already brought in Sir Lynton Crosby, the electoral strategist who delivered David Cameron that majority, and who advised him not to take part in a TV debate.

Jeremy Corbyn and Liberal Democrat leader Tim Farron have both indicated they would be happy to take part. Mr Corbyn has said “if these election is about leadership, she [Theresa May] should not be dodging TV debates”.

Tim Farron has called on the BBC to hold a debate without the Prime Minister, and represent her with an an empty chair. It would be extraordinary if they were to do so.

What result do the latest polls suggest?

The weekend polls give Theresa May a 21-point lead, which could cost Labour 70 of its 232 seats, but the Liberal Democrats, with its strategy of opposing Brexit, could and should regain a significant number of the seats it lost in 2015.

Could there be a new progressive alliance against Brexit?

In the imagination, Nick Clegg, George Osborne, Tony Blair, Peter Mandelson could all very easily slot into a new, pro-EU party. But in real life they will not abandon their own parties. A progressive alliance would, probably, require both main parties to split in two. The would-be splitters will not do it.

Will the vote affect the Brexit negotiations?

Theresa May said she has called the election to give herself a stronger hand in the Brexit negotiations, and if she does do as is overwhelmingly expected and return to Parliament with a far larger majority, it is fair to say her negotiating power will be strengthened.

Whitehall departments have for some time been drafting preparatory legislation to ready the UK for its departure from the EU, with laws that must be passed in Westminster on almost every policy area, on trade, on immigration, on customs arrangements and so on. These must be passed concurrently with the negotiations, and EU negotiators will certainly be emboldened if brutal parliamentary battles form the backdrop to them.

When is the general election vote and when will we get the result?