Labour plans to bar private landlords from raising rents faster than inflation over a three-year period if it wins power after the General Election.
Party leader Ed Miliband described Labour's blueprint as "a plan for a stable, decent, prosperous private rental market where landlords and tenants can succeed together".
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The move forms part of a plan to help the growing number of people - known as Generation Rent - who are stuck in rented accommodation as home ownership falls to its lowest level for 30 years.
Labour has already announced plans for secure three-year tenancies for all those who want them, to protect tenants in a short-term private market where default agreements currently last just six-12 months.
Now Mr Miliband is promising that over the course of a three-year contract, rents would be capped so that they cannot rise by more than the CPI rate of inflation.
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Labour is also offering to ban letting agent fees to tenants, which the party says would save the average renting household £625 over the next Parliament.
Some 11 million people - including 1.5 million families with children - rent their homes. Almost 50% of private tenant households are aged over 35.
Labour claim average rents are £1,200 higher now than they were in 2010, and letting agents' fees have added an average of £355 to the cost of renting a property.
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Labour's Shadow Housing Minister Emma Reynolds told Sky News: "Rent increases should be no higher than inflation during the period of the tenancy, because at the moment there are families with children, who are settling in the private rented sector because they cannot afford their own homes or they cannot get into social housing.
"Sometimes the rent is being hyped up from year to year and they simply don't know what is going to happen.
"We have lots of people over the age of 35 and renting privately, which was not the case 20 or 30 years ago. They need more stability."
But Conservative housing minister Brandon Lewis said: "Ed Miliband is re-launching a policy that descended into chaos when it was first announced - the experts he claimed backed his plans came out and attacked it as unworkable.
"Rent controls never work - they force up rents and destroy investment in housing, leading to fewer homes to rent and poorer quality accommodation. Even Ed Miliband's own shadow housing minister admits they don't work. And an SNP-run Ed Miliband government will put our economy at risk, meaning fewer homes and higher rents."
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