Thousands of flat owners are facing five and six-figure bills for cladding replacement and other fire safety work on flats they bought in good faith. The building defects were discovered in blocks of flats across the UK after the Grenfell Tower fire in June 2017 which killed 72 people.

A group of Tory rebels put forward an amendment to the Fire Safety Bill which would have protected leaseholders in England from paying to fix fire safety defects caused by developers and lax building regulations.

The Fire Safety Bill returned to the House of Commons on Wednesday night. But, following a three-hour debate, the House of Commons voted 340 to 225 in favour of a government motion not to back the amendment.

Tory MP Royston Smith, who tabled the amendment, said voters “will not forget and they will not forgive” if leaseholders are forced to pay for repairs. He added: “Thousands of leaseholders are heading for bankruptcy.”

Home Office minister Kit Malthouse said the Fire Safety Bill was “not the correct place for remediation costs to be addressed”, as the legislation’s only job was to “clarify” that fire safety orders apply to cladding and flat entrances.

He added that the Building Safety Bill, set to be introduced in the spring, would contain “detailed and complex” measures on payments.

A separate attempt to protect leaseholders from unexpected costs was also tabled by Conservative Stephen McPartland and backed by more than 30 of his Tory colleagues.

But McPartland’s amendment was not put to a vote.

Also defeated was an amendment to force the government to implement key recommendations from the Grenfell Tower inquiry. These included making owners tell fire brigades what materials are in wall systems, and carrying out regular inspections of fire doors and lifts. These are all things that contributed to Grenfell’s death toll.

Earlier this month the government announced a £3.5bn extension of the fund to pay to remove defective cladding on buildings over the height of 18m. Those in smaller buildings will be forced to take out loans to fix builder defects. There is also no support for those whose homes are affected by non-cladding related fire safety defects.

Last week a video clip emerged of Brian Martin, a senior official at the Ministry of Housing, Communities and Local Government, admitting that the 18m figure had been “plucked out of thin air”, rather than having genuine implications for building safety.

Giles Grover of the End Our Cladding Scandal campaign said: “The government has failed leaseholders. Tonight, millions will go to sleep feeling trapped and abandoned. We won’t forget this.”

Sarah Jones MP, Labour’s shadow minister for policing and fire, said: “This was an opportunity for the government to do the right thing, instead they have broken their promise to protect leaseholders and implement recommendations from the Phase One Grenfell Inquiry. They have continued in their failure to act and put the British public’s safety first.

“It is shameful that they have voted against implementing vital fire safety measures called for by the Grenfell Inquiry, and it is an insult to people across the country that this government voted down protections for leaseholders from fire safety costs that they did not cause.”

The Leasehold Knowledge Partnership, a charity set up to help and advise leaseholders, has put forward its own funding proposal focusing on a levy on developers, freeholders, and cladding manufacturers.

It says 17% of leaseholders affected by the cladding scandal are considering bankruptcy.