The critical remarks on Friday came amid deep political turmoil in the UK over its looming departure from the European Union - or Brexit, as it is widely known - and growing economic worries over the prospect of a disorderly exit from the bloc.
In a damning report, Philip Alston, UN special rapporteur on extreme poverty and human rights, lambasted poverty rates in Britain's age of austerity as a "social calamity and an economic disaster".
"Fourteen million people, a fifth of the population, live in poverty. Four million of these are more than 50 percent below the poverty line, and 1.5 million are destitute, unable to afford basic essentials," Alston said, citing figures from the UK-based Social Metrics Commission and the Joseph Rowntree Foundation charity.
"The experience of the United Kingdom, especially since 2010, underscores the conclusion that poverty is a political choice. Austerity could easily have spared the poor, if the political will had existed to do so," he added.
The protracted British strategy of budget cutting - although not as draconian as in other EU countries, such as crisis-hit Greece - has seen funding for local authorities and public services slashed and welfare provisions dramatically cut back. According to the Local Government Association, between 2010 and 2020, local councils in the country will have lost 60p ($0.77) out of every £1 ($1.28) the government had provided for services.
"Libraries have closed in record numbers, community and youth centers have been shrunk and underfunded, public spaces and buildings including parks and recreation centers have been sold off," Alston said in his 24-page report.
n his report, Alston accused authorities of remaining "determinedly in a state of denial" over the impact of their fiscal approach.
"The costs of austerity have fallen disproportionately upon the poor, women, racial and ethnic minorities, children, single parents, and people with disabilities," he said.
"In the area of poverty-related policy, the evidence points to the conclusion that the driving force has not been economic but rather a commitment to achieving radical social re-engineering," he added.