More than 80,000 people in the West Midlands will be hit by cuts in housing benefit, charity Shelter has warned.
The housing charity said it was concerned that debate about the changes had focused on London - but tenants across the whole country were likely to be affected.
Ministers have announced a series of reforms including a cap of £400 a week, more than £20,000 a year, in the amount any family can receive.
Critics including Conservative London mayor Boris Johnson have claimed this will force people on benefits out of central London, and could see an exodus of poorer families to neighbouring counties such as Essex.
But Ministers are also planning to cut the Local Housing Allowance - the maximum that people can claim in housing benefit - across the country.
Although this won’t affect everyone, Government figures show that 14,260 households in Birmingham will lose money because of the change.
And they will lose anything between £6 and £17 a week, depending on the type of home they are in. Families in a two bedroom home will lose £11 a week on average.
In Solihull, 1,610 households will lose money while 3,250 have their housing benefit cut in Dudley, 4,160 will be affected in Sandwell and 3,460 will be affected in Walsall.
Currently, the maximum benefit people can claim is based on the rent charged in the cheapest 50 per cent of properties in the private sector. Under the reforms, it will be based on the cheapest 30 per cent of properties.
Across the entire West Midlands region, changes to housing benefit will affect 80,000 people, according to Shelter.
Shelter chief executive Campbell Robb said: “The focus of debate so far has been the cap to housing benefit and the impact on London, but this analysis shows that these cuts will affect over a eighty thousand people in the West Midlands.
“Many are those already on low incomes such as pensioners, those with disabilities, carers and people in low paid jobs who will really struggle to find the extra money they will need to keep a roof over their head.”
But Ministers said they were protecting taxpayers from paying outrageous rents.
Local Government Secretary Grant Shapps said: “Labour’s failure to reform housing benefit has left us in the absurd situation where taxpayers all across he country are paying to house benefit claimants in large houses in expensive areas - sometimes up to £100,000”.
Shelter issued the report as MPs were due to debate the housing benefit reforms in the House of Commons today.