Heidi Allen and Frank Field make an odd partnership at first glance. Allen, 44, the Conservative MP for one of Britain’s richest constituencies, and Field, 76, a Labour MP for 39 years until he resigned over antisemitism in the party, have bonded across the Commons over a shared outrage at poverty. Now they have embarked on a nationwide tour in search of the “other England” shaped by the austerity policies pioneered by Allen’s party. It is proving emotional.

Visits to the poorest corners of Newcastle, Glasgow, Morecambe and Cornwall beckon, but they have started in London and Leicester, where on Thursday they heard stories of an illiterate man sanctioned so often under universal credit that he lives on £5 a week; a man so poor he sold all but the clothes he was wearing; and someone being told to walk 44 miles to attend a job interview, despite having had a stroke, to save the state the cost of a £15 bus ticket.

Time and again Allen, the MP for South Cambridgeshire, with its biotech start ups and affluent villages, was on the brink of tears as they visited two of the 15 food banks now helping sustain people in the east Midlands city and listened to people from charities, playgroups and community organisations. Away from Westminster’s attempt to solve the “mad riddle” of Brexit, Allen admitted that her patience with her party’s acquiescence over the welfare cuts, which started under George Osborne and the universal credit system, now being rolled out by Theresa May, had reached breaking point.

“I have absolutely had enough,” Allen said, eyes reddening, in front of a group who spelled out how the reforms were turning the screw on some of the country’s poorest people. “So I asked Frank if he would join me on a tour of the UK to show the government this exists. Unless we blow the lid off it, my lot are not going to listen.”

Robert Kennedy did something similar in the US in 1968 and gave a famous speech describing “another America” where he found children in Mississippi “crippled from hunger”, people in the “black ghetto” warding off rats, and native Americans living with 80% unemployment. In a similar vein, Allen and Field want to know “how the soft underbelly of our society – – ‘the other England’ – can be strengthened so that none of our fellow citizens are pushed into destitution”, Field said.

“This denotes a new offensive and shows that parliament is aware there is something not wholesome out there in the nation and the nation sees it,” said Field. It follows the tour by the United Nation’s rapporteur on extreme poverty, Philip Alston, who last autumn concluded that the government had inflicted “great misery” on its people with “punitive, mean-spirited, and often callous” austerity policies.

Frank Field and Heidi Allen visit Action Homeless Food Bank in Leicester. Photograph: Fabio de Paola/the Guardian

It was at E2, a community centre and food bank in the deprived Beaumont Leys estate in the north-west of Leicester, where Allen’s tears first welled. Council workers explained they had seen a surge in referrals to food banks since the introduction of universal credit. In June, when universal credit was first rolled out in Leicester, just 5% of people referred to food banks in the estate were on the benefit, but that has since risen to 29%.

The problems poured forth from people waiting to pick up free food. Kate, 68, revealed how her son, who had suffered a stroke, had been sanctioned 15 times.

“The system needs more caring people,” she said. “They are like little Hitlers.”

The woman beside her, who didn’t want to be named, said the bailiffs were set to take back her two-bed council house because she was in arrears, including on bedroom tax. She uses the second bedroom for her granddaughter five nights a week, so her son can work, but that doesn’t count because it is not her child. Without much heating she wraps up in a dressing gown, coat and bobble hat.

The bureaucratic struggle simply to claim benefits is a big problem. Sixty-five percent of the most vulnerable people who come to the council for help don’t have access to a computer, smart phone or an email address, which are needed to fill out forms.

“You must just feel like the world is spiralling around you,” said Allen. “It’s two steps forward and one and a half back.”

After housing costs, 41% of children in Leicester – more than 34,000 – are living in poverty. The Leicester South parliamentary constituency was in the poorest 2% of constituencies in the UK in 2018, which represented a slide down the rankings since 2015.

Over the last two summer holidays, in the most deprived parts of the city, over 15,000 meals were served to almost 1,650 children, using government funds, according to Feeding Britain, a charity set up by Field and which now includes Allen among its trustees.

“If the demand keeps increasing, food banks aren’t going to be sustainable,” Tim Adkin, crisis food manager for Action Homeless, told the MPs at a food bank in a retail unit in the city centre market dressed up to look like a shop, in part to reduce users’ sense of shame. “We can’t keep up with the demand.”

It has seen a 20% increase in year-on-year demand. More and more families with children – now 25% of users – and single women are coming in.

Adkin is among those giving up on central government to change things.

“We are almost in a parallel universe,” Adkin told the MPs. “We are creating our own supply chain for energy and food.”

“If you go into the job centre, there’s a barrier,” he said. “If you come in here, we are not the enemy.”