Tenants are resorting to drastic measures including payday loans and dipping into their children's savings to pay the rent, homeless charity Shelter said today.
Shelter is calling for more stability in tenancy agreements so families are not forced to make "impossible choices" as a result of surprise rent rises.
Calls to the charity's helpline about rent increases or arrears have risen by almost a third over the past year, it said.
Sixty-three per cent of 4,300 people in privately rented housing in England who took part in a Shelter survey said that they are struggling to pay their rent or have fallen behind.
And 26 per cent said they have had rent increases in the last year, with annual rises averaging £300 even as wages remain stagnant.
One in 12 renting parents have been forced to borrow cash from their children to cover bills while one in 33 have taken out a high-interest payday loan to cover rent.
One in seven renters have used a credit card to pay and one in 17 have had to move out because of a rent rise, equating to almost 515,000 people in England.
Rents have soared as many would-be home buyers remain trapped in the rental sector because they have been unable to raise the 20 per cent deposit typically demanded or meet lenders' borrowing criteria.
Shelter chief Campbell Robb said that renters should be given contracts which do not allow above-inflation rent increases.
He said: "This is proof that the growing cost of renting is hitting families where it hurts.
"When families are forced to resort to taking money from their children's savings or paying on a credit card, it's clear that sudden rent rises are pushing many ordinary families to the edge."