Some local services in Northampton have been described as "among the worst in the country" by the public finance watchdog, the Audit Commission.
Lib Dems took control at Northampton council in May
The 2006/2007 report on Northampton Borough Council says that under the past minority Tory rule, planning and housing were rated "poor".
The Lib Dems, which took control in May, pledged to boost its ratings.
Council leader Tony Woods said the previous administration had made some improvements, but more were needed.
The Annual Audit and Inspection Letter goes before councillors on 23 July.
It finds that "overall, the council is not consistently and sustainably improving its most poorly performing" services.
The report says some of its failings "have a direct impact on the quality of life of some of the most vulnerable people".
For example in housing services, the auditors say: "Too many people are evicted for rent arrears, without there being sufficient focus on debt advice and prevention."
The report adds: "The council's weakest services remain among the worst in the country."
It also called "inadequate" the council's performance in financial reporting, financial management, financial standing and value for money.
'Many failings addressed'
It highlights the case of a £1.37m payment by the council to a contractor, in connection with the Far Cotton Community Centre, before any work took place or any legal document was completed.
Mr Woods, the leader of the new Lib Dem administration at the council, said the council had accepted the failings in the report.
"A number of the failings, particularly in the finance area, are already being addressed," he said.
Mr Woods said over the past year or so the planning department had experienced a high staff turnover and this had resulted in some delays.
"This year the report was horrendous - I am quietly confident we are turning this around," he said.
The Audit Commission has rated the authority "poor" over the last three years.