Thousands of leaseholders living in dangerous blocks will not be protected by the latest government attempt to tackle the spiralling cost of the post-Grenfell fire safety crisis, it has emerged, as ministers publish legislation allowing developers to pass on costs to residents. The housing secretary, Robert Jenrick, on Monday introduced a bill extending leaseholders’ rights to sue developers, but residents in at least 239 buildings will not be able to take advantage because their buildings are too old, according to research by the UK Cladding Action Group. Representatives in 79 blocks could in principle sue because their homes were built after 2006, but all except a handful could not afford it. The snap study appears to undermine Jenrick’s claim on Sunday that the “lion’s share” of the buildings identified as fitted with dangerous cladding would qualify under the 15-year retrospective law. Leaseholders are also outraged that the government appears to have decided against legislating to protect homeowners from bills to fix fire safety defects, which in the worst cases run to £100,000 per household. The building safety bill will enshrine the existing legal right of developers and building owners to pass on costs to leaseholders as long as they can show they explored “alternative ways to meet remediation costs before passing these on to leaseholders”. One leaseholder described it as a “slap in the face”. Another said it was devastating. Hundreds of thousands of leaseholders are facing bills to repair fire safety defects that could run to £15bn. The government has so far set aside £5.1bn. The Tory backbencher Stephen McPartland, who has campaigned for leaseholders to be protected, described the plan to help leaseholders sue as “another sticking plaster instead of a solution” and called on the government to “fund making our buildings safe”. He said if the government did not compromise he and allies would lay amendments “to try and protect leaseholders”. Giles Grover, from the End Our Cladding Scandal campaign, said: “Ministers and two prime ministers have promised more than 17 times in parliament that they would protect leaseholders from costs. Now, it seems they have cynically devised a means of divesting themselves from that responsibility.” Rituparna Saha, a co-founder of the UK Cladding Action Group of affected leaseholders, said: “Four years on [from Grenfell] this is the shambolic response from the government instead of tackling the issue head on and making sure buildings that need to be made safe are made safe so people can get on with the rest of their lives. It’s outrageous.” Jenrick has repeatedly said he wants to protect leaseholders from unaffordable costs. Appearing on BBC One’s The Andrew Marr Show on Sunday, Jenrick said: “It should be the builders and the developers who should be paying for this. It is not right that either the leaseholder or the taxpayer has to step up.” Government policy has been to put the onus on developers to volunteer to pay for repairs, which has happened in a few cases, while offering grants where they refuse, but only for works on cladding on tall buildings and not for other fire safety faults. “They have said all along that leaseholders shouldn’t have to pay, but here it is in black and white [that they should],” said William Martin, a leaseholder in the affected Metis building in Sheffield. “I can’t believe that this far on from Grenfell this is all they are doing to protect leaseholders … How on earth does the government think this is adequate?” Lucy Powell, the shadow housing secretary, said on Monday: “We want the government to stick to its promise and legislate to ensure that leaseholders and homeowners will not be faced with the bills for putting these works right … it’s not their fault.” She said Labour would seek to build a cross-party consensus to protect leaseholders as the bill passes through parliament. However, a similar effort this spring failed, despite attracting more than 30 Conservative rebels. The government said in a statement: “The building safety bill, published today, will create lasting generational change and set out a clear pathway for the future on how residential buildings should be constructed and maintained.” The bill will also establish a regulator to oversee safety on high-rise homes and there will be a new construction products regulator with powers to ban dangerous products and prosecute companies that make them. The public inquiry into the Grenfell disaster, which claimed 72 lives, heard the manufacturer of combustible panels used on the building’s facade knew they were dangerous but sold them anyway. A spokesperson for the Ministry of Housing said: “We don’t recognise these unpublished figures. Our new legal measures will more than double the time leaseholders have to seek compensation from developers for substandard building work to 15 years – as long as a claim is started in this time frame, litigation will be able to continue.”