Public libraries lost branches and staff for the seventh year running in 2017-18.
That finding came from the Chartered Institute of Public Finance & Accountancy’s annual libraries survey, which also recorded falls in visitor numbers and lending against 2016-17.
The only increase came in the number of volunteers helping to provide the service in place of paid staff.
Councils’ spending on libraries was down by £30m to £741m and staff numbers from 16,194 to 15,483.
During the year 51,394 volunteers worked for 1.78 million hours, compared with 48,025 and 1.72 million hours in 2016-17.
The number of libraries - whether static or mobile - fell over the year from 3,745 to 3,618 with user visits down from 243.4 million to 233.1 million and the number of books issued from 192.5 million to 182.9 million.
Cipfa chief executive Rob Whiteman said: “We can view libraries as a bit of a canary in the coal mine for what is happening across the local government sector, as we see it reflect many wider trends.
“A lack of funds is forcing many councils to get creative in how they deliver their services, and we find in our public libraries this loss of paid employees is creating a reliance on volunteers.”
Mr Whiteman said similar trends could be seen in other service provision, such as green waste collection, and called for “some honest conversations about the direction of travel of our councils and what their role is”.