More than half of the under-40s will be renting by 2025, home ownership will drop to about 60% and the number of households renting privately will rise to 7.2m

The forecasts come from accountancy firm PwC, which says the pain for younger people will worsen within five years.

Seb Klier, of Generation Rent, last evening told Channel 4 News that there could be “radical action” ahead. Protesters angry at the cost of private renting and being squeezed out of home ownership could show their anger through rent strikes and vigorous opposition to evictions.

PwC says house prices will rise at an average rate of 5% a year, putting the average house price at £360,000 by 2020.

Based on first-time buyers needing to find a deposit of 18%, that would mean having to raise a deposit of £64,800 to get on the housing ladder in 2020.

PwC also says that the contrast will become more marked between the young – who are unable to buy – and the old, many of whom will own their homes outright because they have either paid cash or paid off their mortgages.

The firm predicts that the number of homes owned outright will rise from 8.4m now to 10.6m by 2025, equating to 35% of the total.

Richard Snook, senior economist at PwC, said: “Driven by a decade of soaring house prices before the financial crisis and lower loan-to-value ratios post-crisis, the deposits needed by first-time buyers have risen significantly.

“As a result, a generation of private renters have emerged and this will increasingly be the norm for the 20 to 39 age group.”