Shelter wants government action to protect tenants
There has been a "steep rise" over the last six months in numbers of tenants evicted after landlords defaulted on mortgages, Shelter has warned.
Tenants can get just days' notice to leave their home, says the charity, which wants ministers to "act quickly to give tenants far, far longer".
The government says legislation coming into force in April could entitle tenants to up to seven weeks' notice.
It says it is also considering reforms to give more protection to tenants.
About three million homes in England and Wales are rented from private landlords.
"What we're seeing already is a steep rise in the number of tenants, entirely blameless individuals, who are becoming homeless because their landlords can't pay their mortgage and their homes have been repossessed," said Shelter chief executive Adam Sampson.
"What the government must do is to act quickly to give tenants in those circumstances far, far longer to find themselves somewhere else to live, in a housing market where housing is in desperate short supply."
Mark Sullivan, a 34-year-old jeweller, began renting in Woking, Surrey, in February last year, and said that "almost immediately" threatening letters for the owner - who was uncontactable in the United States - began appearing.
"When we contacted a debt-collecting agency who were writing to the owner - because we needed to know what was going on - a letter stated that no monies had been paid on the mortgage for four months before we had moved in.
"Eventually I was given about two weeks to leave the property just after Christmas. At the time, we still had to wait for our deposit to be returned and find a new deposit for our new property and I had to borrow off my mother.
"The most annoying part of it is that the letting agency were so scrupulous with us. We were credit-checked and had to provide proof of income for ourselves. They don't do the same thing for the owner, whereas we are made to feel almost criminal."
Steve Donnelly, 39, an electronics engineer, took on a three-bedroom townhouse with his partner a year ago in Oakenshaw, Bradford.
"It turned out that the landlord had purchased two properties on the street but never paid a penny on the loan, and then went back to Africa while myself and our neighbours paid the rent for six months," he said.
"We also had numerous people calling over other debts this man had, and even had a tow-truck turn up trying to repossess our car."
"Repossession agents started knocking on the door. The owner obviously had financial problems and as soon as it started happening we started looking to buy a house. One letter from the mortgage company addressed to us said we might have to move out within two or three days."
Mr Sullivan and Mr Donnelly both felt they should have enjoyed some form of security by renting through reputable lettings agencies.
Ian Potter, of the Association of Residential Letting Agents, said landlords were often "in denial" about their situation. "Once the court proceedings take place and he's lost his property, he's lost interest and therefore doesn't bother to tell the tenant."
The government is considering a major overhaul of the sector, although it will not say when this might happen.
"What we are trying to do is to get rid of the unfairness," said housing minister Iain Wright.
"If a tenant is up-to-date with rent and if they're not in arrears, it's unfair that they have their home taken away from them. We're trying to work with Shelter and others to protect the tenant as much as possible."
Current advice to tenants is not to ignore post addressed to the occupier, which could contain a valuable warning.