Many councils could be pushed over the ‘financial cliff edge' if the £500m of high-needs deficit faced by the sector is not written off, the Government has been warned.

High-needs deficits have been pushing some local authorities perilously close to the limits of financial sustainability for months, with 32 councils asked last year to submit a plan outlining how they would recover their special educational needs and disabilities (SEND) deficits within three years.