Only five out of 467 local government bodies had published their 2022/23 accounts with an auditor’s certificate or opinion by the end of September.
This adds to 456 that are outstanding from previous years, according to Public Sector Audit Appointments (PSAA).
Steve Freer, PSAA’s Chair, said intensive work continued behind the scenes to find a solution to the backlog.
He added: “It is now very clear that an extraordinary intervention of some sort is urgently required to put the system back on track.
“An important strand of any solution must be to address the root causes of so many delayed opinions so that, following its implementation, the delivery of timely opinions is firmly and permanently re-established.”
Cllr Pete Marland, Chair of the LGA’s Economy and Resources Board, said: “Councils have a statutory duty to publish audited accounts and council staff work hard to prepare these.
“It is unacceptable that, because of delays in audit outside of their control, only five local authorities have been able to do so by the prescribed deadline.
“The causes of the crisis in audit are not simple. It has long been recognised that they are multi-faceted and complex and will take time to address.
“It will take a concerted response from a range of organisations, including the Government, audit firms and regulators.
“We are urging these parties to work together and for the Government to set a firm timetable by which timely audits will be restored.”