So, the parliament that will go down in history as the one that could neither pass Brexit nor block Brexit has finally voted itself out of existence.

Come the very early hours of Wednesday 6 November, this parliament will be dissolved, and the election campaign proper will begin.

Once the Halloween horror show of a no-deal Brexit had been taken off the table by the EU agreeing to the British request for an extension of the Article 50 deadline (the third one, and Donald Tusk warned in a farewell tweet to the British people, probably the last one), the way was clear for the opposition parties to give Boris Johnson's minority government the votes it needed to call an election.

On Monday, Mr Johnson tried and failed for the third time by trying to use the fixed term parliament act route of securing a two thirds majority of the house for an early election - a very high bar of 438 votes.

On Tuesday he tried an alternative route, a short bill - a one liner, simply setting the date for an election.  And it only needed a simple majority to pass it.

The Liberal Democrats and the Scottish National Party had offered such a route last Friday, but the government declined. 

The reason? 

The two opposition parties had wanted him to park the Withdrawal Agreement Bill until after the election had been held. Mr Johnson naturally wanted to go into the election with Brexit done.

But by Monday he conceded on that issue, and got the SNP on side. Their 35 votes were all he needed. The Lib Dems also came on board.

Labour were going to look foolish, having called - according to Mr Johnson - 35 times this year for an election, but having refused it on the three occasions it was offered. So Labour changed tack and backed the early election bill.

But not without some drama - putting down amendments to try and extend voting rights to EU citizens, and making 16 the legal voting age (as it is in Scottish and Welsh local and assembly elections).

This could have added an estimated four million potential voters to the register - but making a new register would not have been possible for an election this side of Christmas. And it would add to the cost of the bill.  A simple one liner was looking anything but simple.

The amendments were not accepted, and not put to the committee of the house.

In the end, they voted the bill through the final stage by 438 votes to 20.

Hang on - 438 votes? Yes indeed - the number they couldn't achieve 24 hours previously to give the required two thirds majority under the Fixed Term Parliament Act, and get the job done a day early.

So 12 December is polling day.

But having escaped Halloween, the new horror story may be Friday 13th. That's the day when, ordinarily, the people of the UK would wake up to discover who the prime minster was, the result having become clear in the early hours.

But opinion polls are indicating extraordinarily high levels of uncertainty, and that - combined with the first past the post electoral system - makes this election incredibly difficult to forecast.  A small movement either way could prove decisive.  

No wonder so much attention has been paid to the date of the election - Monday 9 December or Thursday 12 December - that was in large part due to a concern about students voting (or not) in their university town as end of term draws near (also on Friday 13 December).

 Apparently there are some very tight university town seats where the student turnout could make all the difference.

What makes this election so hard to call is that it is a four-way race.

The Conservatives, forced to stand as the Party of Boris Johnson’s Brexit deal; Labour saying they will renegotiate their own deal and put it to a referendum (and campaign to remain); the Liberal Democrats who want to stop Brexit, plain and simple, and the Brexit Party, which argues for what it calls a "clean break" - better known to the rest of us as a no-deal Brexit.

These fissures reflect the divided nature of the UK on this issue (The SNP will campaign to keep the UK in the EU, but if it fails it is boosted in its aim of securing Scottish independence).

A four-way electoral fight and a strong regional party is, dare we say it, typically European. All across the EU the old two or two-and-a-half party systems have fragmented into a multiplicity of competing forces, with coalitions the norm. Look at Spain, look at Germany. Look at Ireland.

Look at Northern Ireland, and the different outcomes in the Westminster election, and the Assembly election, which uses a proportional representation system. 

The big difference with the UK is of course that first past the post electoral system. It means a party on 35% of the national vote can win a majority of seats.

But it also means that if the percentages shift, even a little, the big party can lose big too. In a two party fight the "swing" was the thing to watch.  But that is much harder to analyse given that the UK is looking more like a four party system - apart from Scotland.

The really scary thing for anyone hoping the election will sort out Brexit is that it may fail to do so.  

We could end up with a new parliament, with new faces on the benches, but confronting the same old problems - neither capable of getting Brexit done, nor of stopping it entirely.

Meanwhile, don't forget to change your Brexit clocks to 31 January.