London's homeless families could rise by 5,000
The number of homeless families in London could increase by 5,000 as a result of changes to housing benefits, a City Hall report has said.
The document sent to the Work and Pensions Committee detailed what it described as "unintended consequences".
About 9,000 families could be forced to leave their homes, with many pushed outside London by 2012, it said.
Welfare reform minister Lord Freud said "people will have to move" and "adjust to where they can afford".
The document from the Mayor of London's office highlighted the impact of the changes announced by the government last October, which included a proposed £400-a-week cap on housing benefit.
London could see a rise in rent arrears, eviction, homelessness and families needing temporary accommodation, doubling the amount spent by London councils on accomodation to £78m, the report said.
It could also result in about 6,500 of the 9,000 families moving out of the area they live in as rents become unaffordable.
The document, published in December, added that Camden, Hackney, Hammersmith and Fulham, Islington, Kensington and Chelsea, Tower Hamlets, Westminster, Brent, Hackney and Wandsworth, will become unaffordable.
City Hall proposed that families with children living in these areas be exempt from the housing cap and asked the government to ring-fence most of the Discretionary Housing Payments for London.
Lord Freud said the government was not expecting "dramatic perceptible increases in homelessness".
"People will have to move but people move a lot in the private sector," he said.
"So that's nothing new..that process will continue and people adjust to where they can afford just like anyone else.
"People in London have to travel a lot, it's a commuter place. This is just what it means to live in London."
In October, Mayor Boris Johnson said London would not see a "Kosovo-style social cleansing" and will not become like Paris "where the less well-off are pushed out to the suburbs".
Lord Freud said: "London is so different from Paris.
"London is a series of villages. It isn't the kind of doughnut-shaped, the rich inner and poorer outer, that Paris has. We have much more of a patchwork."
Waltham Forest's lead member for housing and development, Councillor Marie Pye, said outer London boroughs did not have space to accommodate people moving out of central London.
"It's not a risk, it's a reality," she said.
"They (people moving) will try and come to places a little bit further out, like Waltham Forest, but there is no space here, so where are they going to go?"