Boris Johnson has been Prime Minister for just six weeks.

He's barely had time to unpack at 10 Downing Street but is now demanding an election.

Why would he risk losing the top job - something which would see him become Britain's shortest-serving PM, breaking an almost 200-year-old record?

On Thursday morning (Australian time) a majority of Lower House MPs voted for the Government to demand an extension for Brexit from the European Union (EU).

They want to stop Mr Johnson taking Britain out of Europe without a deal next month.

Sum it up for me. What happened in British Parliament overnight?

Members of the House of Commons passed a bill to prevent a "no-deal" exit from Europe on October 31.

This law would force Boris Johnson to ask the EU for an extension (which is a bit awkward given he just wants to leave).

So, the Conservative Party Government tabled a motion calling for an early election instead, but this didn't get enough support.

(The British PM can't just call an early election whenever they like — the UK has fixed terms.)

What happens now? Has this delay been passed into law?

Not quite yet.

The bill to delay Brexit has moved to the Upper House and needs to pass the House of Lords and be approved by the Queen.

This all needs to happen before Parliament is shut down next Monday (Mr Johnson arranged that too).

Loading

Last night seemed to go well for the no-deal opponents. What about this next stage?

Upper House members arrived at work expecting days of endless trickery and waffle from pro-Brexit colleagues.

There was talk of nearly 100 amendments being debated (including one about, of all things, bat habitats) in a bid to run down the clock before Parliament's shutdown.

But about 1:30am in London (10:30am in eastern Australia) the Government gave up.

It announced that all stages of the legislation would be completed by 5:00pm (local time) on Friday.

Am I right in thinking the PM hasn't had the best week?

The consensus seems to be the bloke's had a shocker.

He hasn't won a single vote in the Lower House since becoming Prime Minister.

In addition to losing his majority, Boris Johnson lost control of the parliamentary agenda. ( Reuters: UK Parliament/Roger Harris )

This week alone MPs voted to:

Hijack the parliamentary agenda.

Hijack the parliamentary agenda. Pass a bill to prevent a no-deal Brexit happening on October 31.

Pass a bill to prevent a no-deal Brexit happening on October 31. Stop him calling an early election.

So, MPs voted against an early poll. Does that mean it's off the table?

Nope.

It's now just a question of when (and how) the election will be triggered.

Boris Johnson no longer has a majority in Parliament after expelling 21 rebels from his own party.

Most MPs from the Labour Opposition deliberately didn't show up to the chamber, to prevent the Conservatives getting enough votes to call a snap poll.

Labour voted against an election? Doesn't it want to, um, win power?

Loading

Opposition parties want the bill preventing a no-deal Brexit to be made law first.

Many also don't like Boris Johnson's preferred date of Tuesday October 15.

Why? Because if he won then he could scrap the bill that passed overnight.

A senior Labour MP told our colleagues at the BBC his party would not support an election being held before October 31.

But there are a couple of other ways Brits could be forced to the polls (again):

Passing a bill to bring on an election (with a simple 50 per cent plus one majority) that explicitly says to ignore the Fixed-Term Parliament Act.

Passing a bill to bring on an election (with a simple 50 per cent plus one majority) that explicitly says to ignore the Fixed-Term Parliament Act. Parliament votes to express no confidence in the Johnson Government.

Who would Boris Johnson replace as Britain's shortest-serving PM?

George Canning served from April 1827 to August 1827.

He was in office for 121 days before dying from pneumonia.

Mr Johnson will have served 100 days on October 31 (if he's still there).

He seems popular enough. Could Johnson's Conservatives win a snap election?

They absolutely could.

Loading

Opinion polls have shown a boost for the Conservatives since Mr Johnson took over.

One survey conducted in late August put the Conservatives on 34 per cent and Labour on 22 per cent.

The Brexit Party has also promised to work with Mr Johnson — if he pursues a "clean-break Brexit" — to avoid splitting the Brexit-supporting vote.

The outfit, led by Nigel Farage, dominated May's European elections in the UK.

But predicting British politics has become a mug's game.

Former British prime minister Theresa May called a snap election in 2017 to strengthen her hand. She lost seats.

And David Cameron called the Brexit referendum thinking "Remain" would win.

How would Brexit be affected if Labour won?

If elected, Jeremy Corbyn's Labour Party would hold another referendum on the options for a Brexit deal. ( Reuters: Andrew Yates )

Labour wants to avoid a no-deal Brexit.

If elected, it would hold another referendum on the options for a Brexit deal.

Remaining in the bloc would be an option on the ballot paper.

Loading

How would Brexit be affected if Johnson won?

If the Conservatives reclaimed a majority in the Commons, Britain would leave Europe with or without a deal.

But if Mr Johnson needed a coalition partner or two, he would be really hoping they want to exit Europe as much as he does.

OK, let's quickly recap

Brexit is due to happen on October 31.

And it will happen, unless one of these things happen: