Official figure doubled from 1,230 to 2,460 in London between 2010 and 2011, and rose again in first six months of 2012.
Nicholas Watt
The number of homeless families forced to stay in basic bed-and-breakfast accommodation in London doubled in the space of a year, according to official figures.
The Labour party said growing numbers of families were paying the price for the government's economic policies after figures showed the number of homeless families staying in B&Bs doubled from 1,230 to 2,460 between 2010 and 2011.
The data, which covers households with dependent children and or pregnant women with no other dependents, show the number staying in such accommodation for more than six weeks trebled from 190 to 560.
Figures for the first six months of 2012 indicate that the housing crisis has worsened. They show that 1,910 families with children were forced to stay in B&B accommodation, compared with 1,020 in the same period in 2011. A record 820 families lived in such accommodation for more than six weeks in the same period - higher than the number for the whole of 2011.
The figures were released by the Department for Communities and Local Government in response to a parliamentary question.
Jack Dromey, the shadow housing minister, said: "Families should not be spending Christmas in bed-and-breakfast accommodation, but under this Tory-led government the problem is getting worse, not better."
Dromey pointed out that Mark Prisk, the housing minister, told Westminster city council this month that its practice of placing families in B&B accommodation for more than six weeks was "unlawful and unacceptable".
Dromey said: "Ministers say that placing homeless families in B&Bs for more than six weeks is 'unlawful and unacceptable', but the problem is getting worse on their watch. More and more families are paying the price for David Cameron's failing economic and housing policies. While millionaires get a tax cut, thousands of families are spending Christmas without a permanent roof over their head."