Several families will find their income is "toast" following welfare reforms despite Theresa May pledging to help those labelled "Jams", the Commons has heard.
SNP MP Drew Hendry (Inverness, Nairn, Badenoch and Strathspey) also claimed Universal Credit, which involves rolling six means-tested working-age benefits into one payment, will push children further into poverty rather than lift them out.
He called on the Prime Minister to speak to those people who will lose out under the reforms, with the SNP tabling a motion noting concerns over the impact of policies pursued by the Department for Work and Pensions on low-income households.
Speaking in the Commons, Mr Hendry said: "The Prime Minister has been talking about Jam - the so-called just about managing.
"Thanks to Universal Credit, for many families their income is about to be toast.
"I suggest the Prime Minister comes to Inverness and talks to my constituents about her 'shared society'.
"To those families with children, who will be up to £2,630 per year worse off, according to the Children's Society.
"To the lone parents and people with limited capability of work under the age of 25 losing £15 a week.
"To the young people and their families who will be pushed further into poverty because of reductions in standard allowances.
"The four-year freeze on support for children will see the value of key children's benefits cut by 12% by the end of the decade.
"Universal Credit will not only fail to lift children out of poverty, it will push them further into poverty."
The Government tabled an amendment to the SNP motion which, among other things, states its welfare reforms have led to more than "2.7 million more people in work and 865,000 fewer workless households" than in 2010.
Work and pensions minister Damian Hinds said the Government has made "great progress" in reforming welfare and creating a fairer system.
He said: "While we have had to make difficult decisions on welfare spending, we have never lost sight of the fact that the most sustainable route out of poverty and just managing is to get into work, and to progress in work.
"Universal credit lies at the heart of this - transforming the welfare system to ensure that work always pays, that it pays to participate, that it pays to progress."
Unemployment is down, income inequality has fallen, the national living wage has been introduced and free childcare is being extended, MPs heard.
Mr Hinds said universal credit is expected to generate £7 billion in economic benefit every year.
He added: "Tackling child poverty and disadvantage, delivering real social reform is a key priority for this Government.
"Only by tackling the root causes of poverty, not just the symptoms, will we make meaningful difference to the lives of society's most disadvantaged children and families."
Shadow work and pensions secretary Debbie Abrahams said the minister's "rosy" depiction of welfare is contradicted by the many Britons walking into MP surgeries every week asking for help.
She said poverty chips away at people's health, life expectancy, educational prospects and even happiness.
"The simple truth is the smaller the gap between rich and poor, the better we all do," the Labour frontbencher said.
"So, when the Prime Minister claims that she wants to tackle these burning injustices, I have to ask her: where has she been?
"These injustices have been burning while she was a senior member of Government, now she's Prime Minister what is she doing to address them?"
She said the answer is "not a lot".
The roll-out of universal credit has been blighted by delays and spiralling costs, she said.
Long waits in payments had driven claimants into rent arrears and food banks, Ms Abrahams added.
Maria Caulfield, the Tory MP for Lewes, said that "no other government in living memory has done more to help low-paid workers than this government" before attacking the SNP.
She said: "Get on and use the powers you have got instead of blaming the UK Government for the benefit problems you have in Scotland."
Carol Monaghan, the SNP MP for Glasgow North West, hit back and said: "It's interesting to follow the member for Lewes because the current policies of this Government have little to do with getting people into employment and everything to do with aggressively targeting the people who most need support."
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