That’s according to a study by Citizens Advice, which found many landlords don’t know their legal obligations, while renters aren’t aware of their rights.

It means many tenants live in homes with health-affecting hazards such as mould or dangerous problems such as not working or missing smoke or carbon monoxide alarms.

Three in five tenants identified disrepair in their home in the last two years that was not caused by them and that their landlord was responsible for fixing.

One in six said the disrepair was a major threat to their health and safety.

One renter contacted Citizens Advice for help because a leaky roof in her building meant rain was dripping into her young child’s bedroom, causing mould. She said her child’s health was being affected by the hazard but that after two years her landlord had still not fixed the problem.

Worryingly, a third of tenants said their house did not have a carbon monoxide alarm despite requiring one. That equates to around 900,000 homes.

Landlords struggling with rules

Meanwhile, a quarter of landlords admitted that they failed to make sure there was a smoke alarm on each floor of all of their properties and the same number failed to carry out an annual gas safety check or make sure that smoke and carbon monoxide alarms were working.

Almost one in three landlords said they found it difficult to keep up with rules and regulations and just half did not know the potential penalty (a fine of up to £5,000) for not checking smoke and carbon monoxide alarms are in working order on the first day of the tenancy. The same proportion didn’t know the penalty for not carrying out a gas safety check.

The government has made reforms in the private rented sector in recent years, such as laws to ensure all rented homes are fit to be lived in, banning most tenant fees, and proposing the abolition of “no-fault” section 21 evictions.

Citizens Advice helped almost 60,000 people with issues related to private renting last year. One in four had issues getting repairs completed and more than 2,500 were being harassed by their landlord.

National housing body

Gillian Guy, chief executive of Citizens Advice, said: “Too many private renters live in hazardous homes – often with potentially fatal flaws.

“Weak and confusing regulation means landlords can struggle to understand their legal obligations, while tenants find it hard to get problems in their homes resolved.

“The government must establish a national housing body to ensure landlords let property that meet legal standards, and gives renters the support they need when they don’t.”