Protesters occupied a library overnight after a national day of action over threatened closures.
A group of about 40 people from the Save New Cross Library Campaign opted to continue their earlier "read-in" until noon today.
Save Our Libraries Day saw more than 100 events held across the UK to bring attention to proposed government spending cuts.
More than 350 libraries are understood to be under threat of closure.
The national day of campaigning saw authors including Philip Pullman and the musician Billy Bragg pledge their support to libraries.
As well as "read-ins", some events involved storytelling, writing workshops and music.
A security guard at New Cross Library in south-east London said about 40 people were sleeping in the building overnight.
Protester James Holland told the BBC: "I think with this occupation we are going to take the libraries campaign - and the anti-cuts campaign in general - to a whole new level. We are just not going to put up with these cuts.
"As far as I'm concerned there's money available all over the place, whether it's from tax-dodging corporations or if its bureaucracies in councils. I think the people who have really failed here are the politicians, it's a total failure of democracy.
"We need to save all public services and we don't need to cut any of them. I don't understand why people aren't looking at the genuine alternatives to fund public services and to getting the money from the people who can afford to pay it - that's exactly the answer."
Lauren Smith, spokewoman for Voices for the Library, said yesterday: "Local councils are having to make these decisions so quickly. Once a library is shut it will never reopen. When councils realise what they have done it will be too late."
The day of campaigning came after a study revealed children who used their local library were twice as likely to be above average readers.
The National Literacy Trust report, based on a survey of more than 17,000 eight to 16-year-olds, revealed that almost two-thirds (64.5%) of those who use the library are reading above the expected level for their age.
For non-library users, this figure is just 35.5%.
Mr Holland, 38, who lives in New Cross and uses the library with his three-year-old daughter, said there were about 10-15 people left at the sit-in this morning but more were expected to join the group.
He said: "There's a lot of disillusionment with the political and so-called democratic process. We felt we needed to take things into our own hands and make the politicians listen.
"Libraries are egalitarian, they are empowering and I can't think of anything more indicative of a civilised society."