Soaring UK rent rises will leave almost six million private renters living in poverty by 2040, according to the Joseph Rowntree Foundation (JRF).
The charity warned that the current generation of primary school children face paying private rents that are 90% higher than the cost of renting at the start of the recession in 2008.
The study, which was conducted by academics at Heriot-Watt University and the University of Sheffield, found that private rents are forecast to rise by twice as fast as incomes.
The average private rent today is £132 ($206, €165) per week – it will be £250 per week in 2040 in real terms.
"These stark findings are a wake-up call for political leaders," said Julia Unwin, chief executive at JRF.
"After decades of failing to build enough, those in power have a responsibility to act now to build more genuinely affordable homes.
"Without that we are storing up trouble for the future – a price that will be paid by children starting school life this year.
"These high costs are bad for families, the economy and government."
The research also revealed that one in five (10.6 million people) will be living in private rented homes, up from 7.2 million today.
JRF said half of these, 5.7 million, will be in poverty (a rise of 2.6 million).
In addition, one in 10 will be living in social housing, down from the current figure of 8.2 million to 5.7 million in 2040.
Social rents will increase 39% to reach £92.10 per week in real terms.
If social rents continue to rise towards market rates, the cost of Housing Benefit could rise by 125% – adding £20bn to the current bill.
The JRF has called on the government and housing providers to work together on an action plan to solve the housing crisis and keep poverty in check.