More than one million struggling British families are spending at least one-third of their income on housing costs, a think-tank has revealed.

Work by the Resolution Foundation shows 1.3 million households on low to middle incomes are spending more than they can reasonably afford on mortgage payments, rent and maintenance costs, forgoing other essentials such as food to pay their bills.

The highest proportion of those families with unaffordable housing costs live in London (16%) and the south- east of England (15%), compared to 2% in Northern Ireland, and 3% in England's north-east.

Vidhya Alakeson, deputy chief executive of the Resolution Foundation and joint author of the report, said: "Many families are struggling to find any type of housing which fits both their needs and their budget.

"Often they are making difficult choices which mean going without other essentials to pay their housing bills or living in overcrowded conditions – at a time when other living costs are rising."

She said people had become used to the idea that buying a property was now an impossible dream for millions on low to middle incomes – in a typical case, she said it would take 22 years just to save the deposit.

The analysis drew on detailed data about how much families are spending on housing, particularly at the lower end of the market.