Concerns over the future of school libraries have heightened with the closure of the service in Cambridgeshire, which the council says was withdrawn due to lack of demand.
The service provided books, resources and expertise to schools in the county.
The closure comes just months after Southwark in London announced that it, too, was shutting its school libraries.
Campaigners are warning that as public sector budgets are tightened, school libraries could be among the first cuts.
Alan Gibbons, who is leading a campaign to make the provision of school libraries statutory, said: "It (the closure) is drastic and it's not the only one.
"It does look as if the school library service (SLS) is the most vulnerable section of library provision because funds are delegated to schools.
"It does not have the statutory support that public libraries do, or the relationship of a school librarian."
Cambridgeshire NUT spokesman Tom Woodcock said the move was part of a wider programme of cuts at the council.
He said: "The council put the case that the schools had not bought into it and didn't need a central service. But teachers we spoke to certainly did use it.
"The library service provides a large number of books and gives schools access to professional expertise that perhaps small primary schools would not be able to sustain alone."
Melissa Stanton, chair of the School Library Association's (SLA) Cambridgeshire and Peterborough branch, said: "I think it's terrible. It really was an invaluable service for primary schools."
The SLA says that at least 32 of the local authorities in England no longer have a school library service.
Most services were originally LEA-run, but since the introduction of local management of schools, funding is often allocated directly to schools, which can then buy into the service if they wish.
Southwark's SLS was closed last year after take-up fell from 67 out of 95 schools to 52 schools.
Cambridgeshire County Council has not released the figures for its area.
It said that the closure of the service had resulted in five redundancies; one member of staff retired.
The council made the decision after its library revenues dropped from #163;1.25 million in the late 1990s to just #163;224,000 last year.
It said only 66 schools subscribed to the library service, out of 200 primaries and 30 secondaries in the county.
Joe McCrossan, head of St Alban's Catholic primary, Cambridge, and chair of Cambridgeshire Primary Heads, said: "It is disappointing that it's not there, but these days schools are working in different ways to support each other.
"More and more schools are working collaboratively and sharing things such as books and artefacts. There are cuts, that is the climate we are in."