MPs have begun hearing evidence at a Select Committee inquiry on library closures.
The Department for Culture, Media and Sport (DCMS) has been requesting views on the service since November.
Witnesses giving evidence on Tuesday said closures would have a negative impact on local communities.
"We're not saying library services should be immune but local needs haven't been taken into account," said campaigner Abigail Barker.
Ms Barker, who represents Voices For The Library, said libraries were not just about lending books.
She argued they were a place where local communities could get together for a number of reasons, including craft and homework groups and a meeting place for over-65s.
Residents and users had not been consulted about cuts, she told MPs.
Campaigners say hundreds of libraries face closure due to local council funding cuts.
Role of librarians
When MPs questioned whether libraries could compete with the technology of the 21st Century, Ms Barker, who is also a librarian, argued there were many online facilities libraries could offer.
"People have an outdated opinion of what a library is. I don't think a lot of people making these cuts understand what a library is, what a library does or what a librarian can offer," she said.
"We should not be looking at the library as a building, but the library as a service.
"The role of the librarian is almost being ignored by these cuts. We're not just there to stamp your books - we're there to enhance your visit to the library. Librarians are as important as the library building."
Sue Charteris, whose report into closures in the Wirral found that they contravened the government's statutory duty to provide library services - also gave evidence at the inquiry.
She said local authorities needed to look at their budgets to assess whether they could they run "a comprehensive and efficient service".
"You can't reduce budgets and expect it to be the same," Ms Charteris said.
"But you need to see where the money is being spent and that needs to be done in consultation with the people that use the library."
The inquiry is due to continue after parliamentary recess at the end of February.