Hundreds of families in Peterborough have had their benefits capped over the last five years, new figures show.
The vast majority of households affected include young children, with charities warning that the cuts risk leaving families homeless or hauling them below the poverty line.
Figures from the Department for Work and Pensions show that between the introduction of the cap in April 2013 and February this year, 691 families had their housing benefits docked in Peterborough.
Couples with children are limited to an annual income from all benefits of £20,000, or £385 a week. In London, the cap is higher, at £23,000.
There are lower rates for single parents and households without children.
Over the last five years, 136 households in Peterborough were docked more than £100 a week. Of those, 13 saw more than £200 a week capped.
The majority of capped claimants, 68%, were single parents with children. Couples with children accounted for a further 30% of cases.
The chief executive of Shelter, Polly Neate, said: "At Shelter we hear every day from families who have been hauled below the poverty line by the cap on housing benefit, with many struggling to put food on the table and keep a roof over their heads.
"The cap is a cruel and ineffective way of achieving what the government claims is their aim of getting people into work, and doesn't account for the wildly varying rent levels across the country.
"We continue to call on the government to urgently lift the cap before even more families are put at risk of homelessness. But we must also see urgent action to build many more genuinely affordable homes for rent, so ordinary families can enjoy a secure future with a safe and permanent place to live."
The chief executive of the Chartered Institute of Housing, Terrie Alafat, said: "The benefit cap is supposed to be about fairness, but these latest statistics show it is fundamentally unfair.
"More than half of the households affected are either lone parents with a child under five or caring for a disabled relative, while another 15% are receiving employment and support allowance, meaning that they are not currently fit for work.
"The government says the cap is supposed to encourage people to move into work, but it is clear that most of the people affected will find that incredibly difficult. And almost half of the households affected are losing more than £50 a week, a huge loss for families on low incomes.
"As a result thousands of families are facing a daily struggle with some being forced to go without food or heating so they can pay for their housing, or falling behind with their rent and being put at risk of homelessness. Unless the government is prepared to think again and either raise the cap or remove it entirely, the consequences could be severe."
With the unemployment rate at 4.2%, its lowest level since 1975, the Work and Pensions Secretary, Esther McVey, said the policy is working.
She said: "Every child deserves the best start in life, and we know that children living in a household with someone in work do better in school, have better educational attainment and are more likely to have a job later in life than children growing up in a home where no one works.
"In the past there could have been families living in cycles of worklessness without the proper support or incentives to move into work with the security and peace of mind that comes from a regular wage.
"We now have record employment in the UK with more than one thousand people moving into jobs each and every day since 2010."
There are several situations in which people are exempt from the cap, including when they receive working tax credits, or claim carer's or guardian's allowances.
In February this year, the most recent month for which data is available, 251 families were still having their benefits capped in Peterborough.
In November 2016, the limit for benefits to be capped was lowered, from £500 a week nationwide. Prior to this, only 48 families in Peterborough were having their benefits capped.
Since April 2013, over 178,000 families in Great Britain have had their benefits capped. Of those, 84% had children aged 10 and under.