Nearly 600 more low-cost rented homes must be built every week to fix the 'broken housing market', according to the Joseph Rowntree Foundation.
But the charity says the Government's current plans will deliver less than a sixth of the number needed.
It says unless the Government ramps up the supply, England will see a shortfall of 355,000 affordable homes by the end of the Parliament.
The foundation is calling on the Government to use its forthcoming social housing green paper to commit to building 78,000 affordable homes a year.
It says this would ease the pressure on families trapped in the expensive and insecure private rented sector, which in London and the South East can account for up to 40% of earnings.
The foundation's chief executive Campbell Rob said: 'The Government’s existing plans risk falling far short of the numbers of affordable homes required to ease the strain on families facing eye-watering private rents.
'Voters across all wage brackets want to see action on housing and it is simply not right that so many people in our country are locked out of the opportunity to build a decent and secure life because of crippling housing costs.'