The council’s planning officers – the equivalent of 12 full-time posts – were dealing with 900 cases, the site and resources control committee heard.

Ms Lee told councillors: “There is a risk of immunity in these cases. This will not apply to all cases.

“Immunity periods for enforcement planning differ depending on the nature of the violation and there are some violations that do not have an immunity period.

“But nevertheless, we have an element of risk around those cases that are more than four years old.”

She said she asked for extra money to cover the arrears.

Ms Lee said there had been two successful prosecutions since 2021, although legal action was a last resort.

Councilor Shane Bartlett, who is responsible for planning, said: “The total number of current cases for the team is too high and it is important that these backlogs are reviewed to reduce any risk of immunity.”

Councilor David Tooke, who chairs the council’s east planning committee, said there was a widespread perception that the council had failed to enforce the rules.

He said: “It is important that we look at law enforcement and try to regain the trust of the general public.

“I constantly have people say to me, ‘There’s no point in implementing it because all you’re doing is going along with whatever they’ve done.’