The cost of housing homeless families in temporary accommodation has risen by 78% in five years to more than £1bn, according to the latest official data.

A combination of soaring rents and more families without accommodation pushed spending on emergency housing to almost £1.1bn in England in the year to April 2019, analysis of figures from the Ministry of Housing, Communities and Local Government shows.

Almost a third of the budget (£344m) was spent on rooms in emergency bed and breakfasts, which are among the most expensive yet least comfortable forms of accommodation, particularly for families, according to housing experts.

Polly Neate, chief executive of Shelter, said the “shocking” increase – up 9% year on year – was the result of a failure by successive governments to build affordable social housing.

“What is even more shameful is that so much of this public money is lining the pockets of unscrupulous private landlords, who can charge desperate councils extortionate rates for grim B&Bs, because there’s nowhere else for families to go,” Neate said.

Shelter’s analysis shows that a 78% increase in spending on temporary accommodation in five years has far outstripped the 45% increase in the number of homeless households needing it. Similarly, the number of homeless families housed in B&Bs has increased by 61%, yet the amount spent on their rents has risen by 111%.

Last month, the Observer found that firms providing temporary accommodation in England’s top 50 homeless blackspots received an average of £10,000 of public money for each booking.

On Thursday, the GMB union called for local authorities to be given powers to take over long-empty dwellings to house homeless people. Research by the union found that in 2018 London had a total of 22,481 long-term vacant dwellings, 2,244 more than the year before. In the same period, 232,409 households were on local authority housing waiting lists in the city.

Neate added: “No family should have to live in a tiny room where there’s nowhere to even cook a meal, or any safe space for their children to play. This is a crisis we cannot allow politicians to ignore during this election. Social housing must be at the heart of every manifesto.”