A north London council left thousands of its tenants at potential risk with a litany of health and safety failings, a watchdog has found.

A probe by the Regulator of Social Housing into Haringey Council homes found it had not completed 4,000 “high-risk” fire safety jobs, and more than 100 homes had the most serious ‘Category One’ safety hazards.

The Labour-run council did not have up-to-date electrical safety reports for thousands of its homes and around 30% of its stock did not meet minimum-required “decent homes” standards.

The regulator’s Kate Dodsworth said on Monday: “The council needs to act urgently to put things right for tenants, and we are monitoring it closely as it does this.”

The council had referred itself to the regulator in January after taking housing management back in-house last year.

It said it had already started taking urgent steps to address the failings, with the number of overdue jobs dropping, and that it would be investing over £400m in its housing stock over the next five years.

Cllr Dawn Barnes, deputy leader of the opposition Liberal Democrat group, said the regulator’s judgement was “completely damning”.

“These failings must be corrected immediately, or the consequences to tenants could be horrendous,” she said.

“Haringey also faces real questions about how this was able to happen, and how long they knew about these issues before action was taken.

“Tenants deserve answers and complete transparency over the issues Haringey is aware of in their properties and when they will be brought up to acceptable standards.”

In a lengthy joint statement, council leader Cllr Peray Ahmet and chief executive Andy Donald said it would earn the trust of tenants and leaseholders by making “real progress” on the quality of the borough’s homes.

“We fully understand that a well-maintained home is a foundation that every person living in this borough should be able to expect,” they said.

“We are very sorry that our residents have not been receiving the quality of service that they should have done. What is important now is that we move quickly to change this.”