Ed Miliband has vowed to ban landlords from renting out properties that do not meet energy efficiency standards.
The energy secretary told the Labour party conference in Liverpool that property investors would have until the end of the decade to spend up to £10,000 on upgrades for each of their rental homes.
Some will have to buy heat pumps or solar panels to achieve an energy performance certificate (EPC) rating of C or higher.
Mr Milliband vowed to ensure “every rented home reaches decent standards of energy efficiency” by 2030, sparking fresh fears Labour will lead a war on landlords.
He said banning landlords from renting out energy inefficient homes would lift one million families out of fuel poverty.
He said: “We all know that the poorest people in our country often live in cold, draughty homes. Many rent from private landlords below decent standards.
“It’s a Tory legacy. It’s a Tory scandal. It’s a Tory outrage.”
It comes as Labour is plotting to impose stricter rules on evictions. Last month, housing minister Matthew Pennycook was understood to be supportive of French-style “hardship tests” that would effectively ban evictions in cases where renters were found to be worse off.
Landlords have faced increasing pressure from red tape and the loss of tax breaks on mortgage interest in the last decade. High interest rates on mortgages have also squeezed margins, prompting some to flee the market entirely.
Labour has also finally passed the much-delayed Renters’ Reform Bill, which bans so-called “no-fault evictions”.
Chancellor Rachel Reeves is also expected to launch a capital gains tax raid in October’s Budget, which has already driven many landlords to sell up.
In London, 22pc of newly listed homes were former buy-to-lets, according to analytics firm TwentyCi – a 10-year high. Critics have warned that the targets will force even more out of the sector, choking supply and further raising rents.
EPCs rate homes on their energy efficiency, with properties graded between A and G. The Government’s initial consultation suggested requiring all newly rented homes to have a minimum rating of C by 2025, and then all rented properties by 2028.
On Monday, Mr Milliband confirmed that all landlords have until 2030 to make the upgrades.
Current rules forbid landlords from renting out properties with a rating of E or lower, while there is no minimum rating for rented social homes.
Almost half of rental properties had an EPC rating of at least C in 2022, official figures show. However, the National Residential Landlords Association warned that almost a third of rental homes were built before 1919, and would be “among the hardest to improve” in Britain.
The trade body has called on the Government to make cash available for landlords to upgrade their properties, noting that “at present, the private rented sector is the only housing tenure without a bespoke package to support work to upgrade homes”.
The Committee on Fuel Poverty has also suggested landlords could be offered tax offsets for improvements, or loans in areas of low rental value.
Read More: Landlords to be banned from renting out homes that are not energy efficient