Sir Keir Starmer accused Liz Truss of being “scared of her own shadow” after she ducked an urgent question on the economy in the Commons.
Responding to Penny Mordaunt, the Labour leader thanked her for answering the question, adding: “I guess under this Tory government, everybody gets to be prime minister for 15 minutes.”
He continued: “Mr Speaker, the country is in an economic crisis made in Downing Street because they’ve lost all credibility.
“Government borrowing costs have soared, mortgage rates have ballooned. Markets need reassuring and there is long-term damage that can’t be undone.
“Once you’ve crashed the car 100 miles an hour, you’ve damaged it for good and you’re going to be paying much more on your insurance for years to come. And it’s working people who will pay.”
He accused the PM of “hiding away” and quipped: “The lady’s not for turning… up,” to jeers from the Opposition.
It comes as Liz Truss fights for her political life after new chancellor Jeremy Hunt ditched the bulk of her economic strategy.
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In an emergency statement designed to calm the markets, Mr Hunt announced the support for household energy bills would be scaled back and “almost all” the tax cuts promised by his predecessor Kwasi Kwarteng would be reversed.
The Treasury said the new measures would bring in £32bn after economists estimated the government was facing a £60bn black hole in public finances with the mini-budget announcements last month.
Senior Tory backbencher Sir Charles Walker said Liz Truss’s position is “enormously precarious” after abandoning almost her entire economic policy just six weeks after taking office.
Ms Truss will meet the moderate One Nation Conservatives group in parliament on Monday evening before an informal reception with her cabinet.