Labour's deputy leader Angela Rayner has accused the government of "not caring about working people" in lively clashes with deputy PM Dominic Raab.
She accused the government of "cutting the income of a worker on £18,000 a year by over £1,100" with tax rises.
Mr Raab - who was standing in for Boris Johnson at Prime Minister's Questions - said the UK was coming out of the pandemic with rising jobs and wages.
But Ms Rayner said it was getting "harder for working people to get by".
And she attacked Mr Raab over his own spending habits, asking him how much his summer holiday at a luxury resort in Crete had cost.
When he did not reply, she claimed someone on minimum wage would "need to work an extra 50 days to pay for a single night at his favourite resort, probably even more if the sea was open".
'Check her facts'
She added: "The very same week that the government is cutting universal credit, working people face soaring energy bills."
She told Mr Raab to "go back to his sun lounger and let me take over", before turning her attention to his "grace and favour" mansion Chevening, following press reports he was unhappy about having to share it with Liz Truss, who last week replaced him as foreign secretary.
"Families across the country are worried about heating their homes while he's complaining about having to share his 115-room taxpayer-funded mansion with the foreign secretary - the truth hurts, doesn't it? - just as his government are making choices that are making working families' lives harder," said Ms Rayner.
"A typical family is facing a tough winter this year: universal credit down a thousand quid; rent up 150 quid; gas bills up 150 quid; taxes up and food prices are soaring. Working people will have to choose whether to feed their kids or heat their homes."
Ms Rayner - who was standing in for Labour leader Sir Keir Starmer - repeated her party's call for the government to cancel the £20-a-week cut to universal credit due on 6 October, which she said would make life harder for working people.
Mr Raab replied: "She should check her facts as Chevening is funded by a charity, not a penny of taxpayers' money.
"Let me also tell her the most disastrous thing for energy bills of hard-working people across the country would be to follow Labour's plan to nationalise the energy companies, which the CBI says would cost as much as £2,000 on bills."
He defended the cut to universal credit, telling MPs: "The UC uplift was always meant to be temporary. We've paid the wages of nearly 12 million workers through this pandemic.
"We're coming out with rising jobs, rising wages. We would have done none of that if we had taken her advice, not come out of lockdown. Labour have got no plan. Our plan is working."