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Homes where students are away at university are among those worst hit
by political editor Paul Francis
An estimated 17,000 people across Kent and Medway could be hit by the government's so-called "bedroom tax", according to figures released by welfare groups.
Charities say the changes in housing benefit rules will mean more people at risk of eviction and problems paying rent.
Across Kent and Medway's parliamentary constituencies, an estimated 17,175 people stand to lose out - either by being asked to pay more rent or to move to a smaller property.
The average rent increase for those considered to have one spare bedroom would be as much as £47 a month more, or £569 a year.
For those with two extra bedrooms, it would be £1,415 a year.
Ashford is the worst affected area according to data compiled by the National Housing Federation, where there are 2,624 likely losers.
Those who are in homes where they are considered to have an extra unwanted bedroom could see their rents increase by £480 a year.
For those in homes with two extra bedrooms the increase would be £857 a year.
In Canterbury, there could be 1,609 people affected - the second highest figure in the county - with annual rents increasing by £525 or £938.
Chatham and Aylesford could see 1,552 people affected, with rent increases of £490 a year or £876 a year.
At the other end of the scale, fewer people would be affected in Tunbridge Wells, with 404 likely losers and Tonbridge and Malling, with 418.
Homelessness charity Porchlight said the changes were an attack on the poor.
Mike Barrett, Porchlight chief executive, said: "These aren't families or individuals living a life of luxury.
"They are normal households who are struggling to make ends meet.
"If something isn't done now to stop this policy then we are certain to see people facing rent arrears and eventually eviction.
"if something isn't done now to stop this policy then we are certain to see people facing rent arrears and eventually eviction" – mike barrett, of charity porchlight
"People are being asked to find more money or uproot their lives and move to a smaller property. Neither of which exists. It's just another driver for homelessness and an attack on the poor."
The Kent Green party joined the attack. Campaigns director Dr Hazel Dawe said: "The tax is indiscriminate and unjust, it penalises the disabled, single parents, families of those recently deceased, foster parents and the parents of children in the army or at university.
"The retrospective nature of the tax makes it particularly unjust as people did not know about the threat to benefits when they took up the tenancy."
But Ashford MP and policing minister Damian Green defended the changes, saying safeguards were in place to protect the most vulnerable.
"The principle is that benefits should go to the right people, but we do
have to keep the budget under control.
"I have concerns, but we have got a quarter of a million social housing tenants in over-crowded accommodation and many are in Ashford.
It is unacceptable for the government to subsidise people to live in accommodation that is too big for them."
Pensioners would be unaffected, as would those who needed full-time care,
he added.
Under the government's welfare changes, those with one spare bedroom would lose 14% of their housing benefit, while those with two would lose 25%.
The government says changes are needed to make better use of social housing and councils have extra money this year to help the most vulnerable tenants and disabled.