At the election in June half of all private renters voted for Labour and Jeremy Corbyn, up from a third who supported the party in 2010.
As home-ownership declines, the Conservatives, in particular, are beginning to worry —as indeed they should.
What makes Britain's housing squeeze maddening is that, unlike many other problems, something can easily be done about it.
Britain needs to get building.
The consensus is that, to keep prices in check, it must put up 300,000 houses a year, double what it erected in 2015-16.
Mr Corbyn says the answer is a huge expansion of public housing, like the one in the Wilson and Callaghan governments in the 1970s.
This would be expensive, especially if such housing was let at below-market rates.
And few Britons aspire to rent from the council for life.
Better would be to unleash the market.
A change to regulations on green-belt land, which surrounds cities and which is designed to block construction, is long overdue.
Far from being a bucolic retreat, much of the green belt is intensively farmed.
By one estimate, more of Surrey is devoted to golf courses than houses.
Within Greater London enough green-belt land languishes to build 1.6m houses at average densities.