Britain has "deliberately removed" much of its social safety net, driven by a political ideology that represents a "clear violation of the country's human rights obligations", a UN-commissioned report said Wednesday.
Philip Alston, the special rapporteur on extreme poverty and human rights, said austerity policies introduced after the financial crisis "continue largely unabated, despite the tragic social consequences".
"The policies pursued since 2010 amount to retrogressive measures in clear violation of the country's human rights obligations," said the report.
The Conservative government dismissed the findings, calling them a "barely believable documentation of Britain" that painted a "completely inaccurate picture" of the country's welfare system.
"The UN's own data shows the UK is one of the happiest places in the world to live, and other countries have come here to find out more about how we support people to improve their lives," a spokeswoman.
"Therefore this is a barely believable documentation of Britain, based on a tiny period of time spent here. It paints a completely inaccurate picture of our approach to tackling poverty.
"All the evidence shows that full-time work is the best way to boost your income and quality of life, which is why our welfare reforms are focused on supporting people into employment and we introduced the National Living Wage, so people earn more in work."
An Australian lawyer, Mr Alston visited Britain in November, and will present his final report to the UN Human Rights Council in Geneva on June 27.
In its summary, he said that "the bottom line is that much of the glue that has held British society together since the Second World War has been deliberately removed and replaced with a harsh and uncaring ethos.
"A booming economy, high employment and a budget surplus have not reversed austerity, a policy pursued more as an ideological than an economic agenda."
He accused the government of being "in a state of denial", saying the motivations behind their policies were not "economic but rather a commitment to achieving radical social re-engineering – a dramatic restructuring of the relationship between people and the state".
Despite being the fifth largest economy in the world, 20 per cent of Britain's people live in poverty, and 1.5 million experienced destitution in 2017, he reported.
"The social safety net has been badly damaged by drastic cuts to local authorities' budgets, which have eliminated many social services, reduced policing services, closed libraries in record numbers, shrunk community and youth centres and sold off public spaces and buildings," he said.
The report called on Britain to reverse measures such as the benefit cap and a reduction in housing benefits.
It also urged the government to restore local-government funding.