Labour's finance chief today blasted a "Tory tombola" of uncosted tax cuts by rival leadership hopefuls.
Shadow chancellor Rachel Reeves lashed out at candidates who have made a swathe of promises without explaining what they plan to slash.
She told an audience in central London: "Any lingering sense that the Conservatives are the party of economic responsibility has been shredded to pieces over the last few days.
"Instead of setting out serious plans to help people with the cost of living crisis, just as we hear terrifying estimates of what's going to happen to energy bills come October, we're presented with an extraordinary spectacle of a Tory tombola of tax cuts, with no explanation of what public services would be cut or how they would be paid for."
Ms Reeves continued: "The level of unfunded tax cuts being banded around this week would blow a massive hold in the public finances."
She accused Tory leadership candidates of taking a "flamethrower" to financial responsibility rules which were only approved in January - pledging to stick to her own policies with "iron clad discipline".
The Labour frontbencher, speaking at a Resolution Foundation conference in Westminster,. said: "Every single Conservative leadership candidate supported the government’s fiscal rules when they were passed into law in January, but now they are prepared to take a flamethrower to them.
"I’ve set out the fiscal rules which will bind the next Labour government.
"Rules which I will stick to with iron clad discipline."
The shadow chancellor said Labour would set up an Office for Value for Money, which would ensure "every pound of public money would be spent with the respect it deserves".
She hit out at stagnation under the Conservatives and spiralling inflation, saying: "The reason the Tories have become a high tax party is because they've become a party of low growth.
"When you've got low growth you don't have the money to invest in public services."
Ms Reeves said that under the last Labour government, the UK economy grew at an average of 2.1 per cent per year, compared to 1.5 per cent under the Tories.
"We shouldn’t kid ourselves that this is solely a product of global trends," she said.
Shameless Boris Johnson today boasted he will leave office with his “head held high” in an unapologetic PMQs.
The Prime Minister broke cover in Parliament for the first time since he sensationally resigned on Thursday.
After sleaze scandals over parties, ethics, donors and the £112k renovation of his flat, he finally forced out by his own MPs over claims he lied about what he knew of sexual harassment claims against a whip.
But in a rowdy session that saw two MPs get chucked out, Mr Johnson today said he was “proud” of his record in a defiant statement - even as Tory leadership contenders jostle to wipe out his record on tax and the government tables a confidence vote in itself.
And he hinted it could be his last Prime Minister’s Questions, despite the fact he is due to turn up next Wednesday for the last time.
Mr Johnson suggested the leadership contest could be cut off early before a ballot by members, despite the fact all contenders have voted to fight through the summer until a new leader is picked on September 5.
