Humza Yousaf's future as first minister is hanging in the balance today ahead of a motion of no confidence next week.

Now, as leader of a minority government, his fate may be hanging on just one vote - that of a former SNP leadership rival. 

We take a look at how:

The numbers

In the Scottish parliament, the SNP has 63 seats out of 129, two short of an outright majority;

The Greens have seven;

The Conservatives 31;

Labour has 22;

The Liberal Democrats have four;

There is one Alba MSP;

There is also one presiding officer Alison Johnstone, who is both an MSP and Scotland's equivalent of the Commons speaker.

How the numbers are expected to fall

The motion of no confidence was brought by the Scottish Conservatives.

The Greens, Labour and the Lib Dems have all said they are backing the motion.

That would translate into 64 votes against the first minister versus 63 SNP votes.

So the one Alba vote is expected to be key.

How it may all come down to one ... Ash Regan

Once an SNP leadership rival to Mr Yousaf, Ash Regan defected to Alex Salmond's Alba Party last October. 

If she backs Mr Yousaf then that would mean both sides have 64 votes.

Ms Johnstone would then be expected to vote in favour of the status quo, so the first minister would survive.

But if Ms Regan votes against Mr Yousaf, then the opposition parties will have 65 votes against the SNP's 63, and the first minister would lose.

He wouldn't be compelled to resign in this situation, but he'd be under huge pressure to step aside.

More to come

And remember, Scottish Labour say they are going to lay down a motion of no confidence in the Scottish government, which would trigger a separate vote (see post at 10.12am).

Scotland's embattled first minister is expected to make a "major announcement on housing" in the coming hours, sources close to Humza Yousaf tell Sky News. 

Sources say he will not be resigning. 

Mr Yousaf is expected to speak to the media this afternoon. 

It comes after he cancelled a speech he was due to deliver on independence in Glasgow this lunchtime (see previous post).

Labour's rail plan is a landmark moment.

Unlike many aspects of the party's policy offers to date, it is detailed, comes with a blueprint for what will happen on day one, and Whitehall will understand how to implement it.

It is, after all, winding back the clock.

Even the rail companies themselves say change to the train network is needed - though they inevitably don't like this version of their future - and it is not without controversy.

But the row is a fight Labour want to have.

After months of a pro-business love-in from Rachel Reeves and the Labour leadership, it is the single most concrete measure worrying business so far, according to figures from FTSE 100 firms I talked to this week.

They are watching closely to see whether the tendency to squeeze and bash business, evident under ex-leader Jeremy Corbyn, remains in the party's DNA, even if it is well hidden.

Sir Keir Starmer's plan allows the railway companies to come back into public ownership within five years.

But will it leave the railways better off?

Read the full analysis here:

Labour have promised to renationalise nearly all passenger railways within their first term if they win the next election.

But will it leave the railways better off?

On the Sky News Daily, Niall Paterson speaks to Sky's political correspondent Sam Coates to discuss the actualities of Labour's plan and assess if a Great British Railway would be more efficient and cost-effective than the current privatised system.

Paterson also speaks to the editor of Rail magazine, Nigel Harris, to discuss the current state of our railways and what he believes needs to change.

Elsewhere in politics, the Scottish government has ended its power-sharing agreement with the Greens.

Sky's Scotland correspondent Connor Gillies discusses the implications of this for both parties – including a motion of no confidence in First Minister Humza Yousaf. 

The Scottish MSP who may well have the deciding vote in a motion of no confidence in the first minister says she has written to him requesting a "reset". 

But she says she remains "open to any discussion".

Ash Regan, once a rival to Humza Yousaf for SNP leader, defected to Alex Salmond's Alba Party last year.

With the SNP now a minority administration and the rest of the opposition confirming they are plotting to oust the beleaguered first minister, Sky's Scotland correspondent Connor Gillies says Ms Regan finds herself as possibly the most powerful woman in Scotland.

In a post on X, Ms Regan said: "I have written to Humza Yousaf this morning requesting a reset, and a return to competent government, where we prioritise independence and protect the dignity, safety and rights of women and children. 

"I remain open to any discussion where we progress the priorities of the people of Scotland."

You can read more from Connor's analysis on Ash Regan here:

The optics are "tricky" for Scotland's first minister as he cancels a major event while embroiled in a fight for his political future, Sky's Scotland correspondent Connor Gillies says.

Humza Yousaf has cancelled a speech he was due to deliver on independence in Glasgow this lunchtime (see previous post).

Connor says it has been an "incredibly troubling time" for Mr Yousaf after the Scottish Greens said they would join opposition parties in backing a no-confidence motion in him next week (see post at 6.30am).  

It comes after Mr Yousaf ended a power-sharing agreement with the Greens yesterday in a move Connor says "backfired, potentially sensationally".

"No one predicted what would happen in the last 24 hours," Connor says. 

"What will happen in the coming 48 hours? Who knows..."

Scotland's First Minister Humza Yousaf is to cancel a speech he was due to deliver on independence in Glasgow this lunchtime, Sky News understands.

The first minister's future is in the balance after the Scottish Greens said they will join other opposition parties in backing a motion of no confidence in him next week (see that post at 6.30am). 

However, he will not be resigning today, Sky News understands.

A source close to Mr Yousaf told Scotland correspondent Connor Gillies last night that he will not be quitting and is "coming out fighting" (see post at 8.38am).

The government "wants the credit" for falling inflation, but "didn't want to take the blame" for rising inflation, Labour's shadow business and trade secretary tells Sky News

"I think that inconsistency is fair to point out," Jonathan Reynolds says. 

He was responding to a question on whether, when blaming the government for rising costs of energy, food and fuel, his party can really say it wouldn't have been the same under a Labour government. 

He says Labour would look at why inflation was higher in the UK than in comparable countries and what it can change in future. 

He says the UK's "very significant exposure to fossil fuels, particularly gas prices," was partly to blame.

"That's why Labour's plan is for that sprint to clean, renewable energy and more nuclear energy to make sure we are never as exposed as that again."

People in Scotland "need change", shadow business and trade secretary Jonathan Reynolds tells Sky News, after Scottish Labour said they will back a motion of no confidence in First Minister Humza Yousaf. 

"It really does take something to make the Conservative group in Westminster look stable and organised, but the SNP have managed to provide that," he says. 

He says when he is in Scotland people tell him "they don't have one failing government, they've got two".

"They desperately want governments in both jurisdictions working together in a way which is about tackling the real problems people face," he says. 

He was responding to a question on whether Labour in Scotland were "putting party above country" by backing the tabled no-confidence motion and calling for new elections in Scotland.  

He says people across the UK are facing a choice between a "changed Labour Party focusing on growing the economy, or more chaos is under the Conservative Party across the UK or the SNP in Scotland".

"People want a chance ....  to have their say on those things," he says.

"The sooner they get it across all of the UK, but particularly in Scotland, the better it will be."

Mr Yousaf's political future hangs in the balance as the Scottish Greens, Labour and Lib Dems all say they will back the motion put forward by the Conservatives (see post at 6.30am). 

However, Sky News understands the first minister will not be resigning today (see post at 8.38am).