Windsor and Maidenhead BC has warned it could be facing effective bankruptcy if financial support is not agreed soon.
The borough has begun talks with the Department for Levelling Up, Housing and Communities in the hope of securing exceptional financial support.
Windsor and Maidenhead, which limited all non-essential spending in September, said it had uncovered unexpected historical costs.
It warned it had ‘extremely low financial resilience' with reserves in April 2023 at an unaudited £10m – the lowest known reserves of any unitary authority – and debt that had increased from £59m in 2014 to £204m by March 2023.
A statement from the borough said that access to additional funding would give it the ‘breathing space' needed to reduce the risk of having to issue a section 114 notice.
Cabinet member for finance, Lynne Jones, said: ‘Due mainly to historical decisions, the council simply doesn't have the financial resilience to manage the risks ahead, which is why we've begun discussions with Government about additional support.
'This will give us the time and capacity to deliver our plans and achieve the transformation needed to become financially sustainable while continuing to maintain services for residents.'
