Liz Truss's premiership has been plunged into crisis after her Government's tax-cutting bonanza triggered days of economic turmoil.
The Bank of England was forced to make an emergency intervention today to counter the “material risk to UK financial stability” after Chancellor Kwasi Kwarteng's mini-Budget spooked markets.
Labour has demanded Parliament be recalled and an urgent statement be made by Mr Kwarteng over how he plans to "fix the crisis that he has made".
The unfolding chaos has served as an extraordinary backdrop to Labour's annual conference in Liverpool, where Keir Starmer sought to contrast his party's plans for the economy with the Government.
But what would Labour actually do?
Here's what you need to know.
What is happening?
Events have been moving quickly. Only days ago, Chancellor Kwasi Kwarteng unveiled a mini-Budget with £45billion worth of tax cuts, mostly benefitting the wealthiest Brits.
Mr Kwarteng scrapped the 45p top rate of income tax and knocked a penny off the 20p basic rate, as well as reversing a planned hike to corporation tax and slashing stamp duty.
He also scrapped the cap on bankers' bonuses and confirmed the cost of the vast energy bills support scheme.
The massive spending spree, designed to boost growth by 2.5% a year, was known as a mini Budget as there were no proper forecasts.
It involves an extra £72billion of borrowing this financial year alone - much of it funding a £60bn freeze on energy bills.
Mr Kwarteng also did an interview with the BBC on Sunday where he hinted at further tax cuts, spooking the markets even more.
By Monday morning, the pound had hit an all-time low against the dollar and speculation began that the Bank of England would intervene to raise interest rates.
The International Monetary Fund (IMF) issued an extraordinary statement today, saying it was "closely monitoring" developments in the UK and urged the Chancellor to "re-evaluate the tax measures".
The Bank of England today stepped in to buy Government bonds - known as gilts - to prevent borrowing costs from spiralling out of control and stave off "material risk to UK financial stability".
What is Labour's plan for the economy?
Labour were keen to draw clear dividing lines between their plans and the Tory agenda as chaos unfolds in Westminster.
Keir Starmer used his big conference speech to insist they were the party of "sound money" and to accuse the Tories of "losing control of the economy".
Labour would reverse most of the tax cuts imposed by the Chancellor, which economists say would disproportionately benefit the most wealthy.
Shadow Chancellor Rachel Reeves said they would reinstate the 45p top rate of income tax - which was expected to cost around £2billion a year.
Labour would use this cash to fund a major NHS workforce expansion and breakfast clubs for all primary schools in England.
They would press ahead with the planned corporation tax rise but they would keep the 1p cut to the basic rate of income tax.
Mr Starmer also hinted that the party could look at introducing a wealth tax.
Pressed on the issue, he told LBC: "We’re looking at how we tax fairly. On wealth, I’m looking at whether and how we tax all different forms of income.
"Some people earned their income through wages, others earn income through stocks and shares and dividends.
"And we’re looking at what is a fair way to tax all income. It’s not a wealth tax. It’s looking at different forms of income."
Labour would also create a new National Wealth Fund, a state-backed investment fund to invest an initial £8.3bn in green projects.
How is it different to the Tories?
The main difference is taxes.
Liz Truss and Kwasi Kwarteng are betting the house on the idea that they can fire up economic growth by slashing taxes so people have more money in their pockets.
But this is looking like an increasingly dangerous gamble.
The Tories have been bullish about the fact that their plans also disproportionately benefit the richest. Liz Truss has effectively admitted this several times.
Whereas Labour would scrap the tax cuts for the wealthiest and Ms Reeves said she would look at boosting the minimum wage on her first day in Government.
The other clear dividing line is green. Labour wants to turbo-charge green infrastructure projects while the Tories want to bring back fracking and North Sea oil and gas drilling.
Will Labour's ideas be enough to fix the crisis?
In short, we don't know.
Labour's insistence that all of its plans are costed is a deliberate attempt to distance itself from the Government's refusal to allow forecasts - which hasn't helped the jittery markets.
Easing up on the unfunded tax cuts is likely to help but Labour also has big plans for borrowing.
The party doesn't have to set out its full plans as it's not in Government - and you can bet by the time it gets a chance, Labour will be ready.
