Hundreds of council tenants are waiting for overdue gas safety checks in what has been called a "incredibly serious" oversight.
East Kent Housing - which manages social housing on behalf of Canterbury, Folkestone and Hythe, Dover and Thanet councils - admitted last week that as of May 24, a total of 544 properties had an overdue Landlord Gas Safety Register assessment (LGSR).
Since then, the council has intervened and hundreds of homes have now had the checks. There are still 183 properties across the four districts waiting for a full inspection.
It is a legal requirement landlords arrange a gas safety check by a registered engineer every 12 months, as unchecked appliances can leave occupants at risk of carbon monoxide poisoning.
Canterbury City Council has apologised to its tenants on Facebook and Twitter and says it is urgently investigating how the situation arose.
Of the overdue homes, a total of 338 have now had the safety tests carried out and a further 23 are booked, either through appointments with residents or forced entry.
"We're sorry to those East Kent Housing (EKH) tenants who are waiting for overdue gas safety checks," a spokesman said.
"As soon as we became aware of the problem, we worked as quickly as we could to secure the services of extra gas engineers. The number of outstanding checks is falling.
"East Kent Housing has been in touch with the tenants directly to arrange appointments and are offering evening and weekend slots.
"We are urgently investigating how this situation arose and are taking immediate steps to ensure it does not happen again."
Alan Baldock, the leader of Canterbury City Council's Labour group, said the situation was "absolutely unacceptable".
"It's an incredibly serious oversight of safety. The council would certainly expect private landlords to behave in a very different manner and I'm sure they would be incredibly annoyed if they came across a private landlord who was flouting the law, as far as gas safety is concerned," he said.
"It's even more incredulous a huge company doesn't have the management structure in place to ensure this doesn't happen."
Earlier this year, Canterbury city councillors voted to hand East Kent Housing an extra £214,250 each year to improve its services, bringing the total sum it pays the provider annually to £3.1m.
The social housing provider, created in 2011, asked for the cash injection after the authorities raised concerns about several areas of 'weakness'.
"I'm reassured they are getting on with it, but what worries me is this is one of a catalogue of things that is going wrong [with East Kent Housing]. We can all carry on and do things when someone tells you to do it, but that's not the way to run your life," Cllr Baldock continued.
"It's absolutely unacceptable in every circumstance and Canterbury City Council must take responsibility, and should have always taken responsibility for the management of this contractor."