Thousands of families in Derbyshire were hit by the bedroom tax in August, according to figures.
The data shows 1,131 people in north-east Derbyshire, 1,099 in Chesterfield, 828 in Bolsover, 804 in Amber Valley and 337 in the Derbyshire Dales are seeing their weekly housing benefit cut as a result of the Government’s tax - losing out on almost £3,800 in total per year.
The tax is designed to encourage people to downsize and in turn free up empty bedrooms.
But it has come under fire due to the lack of smaller properties available for people to move into.
Kate Warburton, of the National Housing Federation in the East Midlands, said: “There simply aren’t enough smaller social homes available and the cost of private rented housing is rising all the time.
“The bedroom tax is trapping many people in homes they can no longer afford and where they are struggling to pay their rents.
“It is unfair, badly designed and must be repealed,” she added.
The Government said it is committed to supporting people move into more suitable sized properties.
Minister for Employment Esther McVey said: “It cannot be right that there were 2.1 million households on the housing waiting list in Great Britain, yet about one million spare rooms in social housing that were funded by benefits.
“On top of this, 375,000 families have been living in cramped, overcrowded accommodation in England and Wales alone.
“Clearly this was wrong and fairness had to be brought back to this outdated system.
“By removing the spare room subsidy, we can start to ensure the right properties go to the families who need them most.”