Campaigners are preparing to go to the Court of Appeal after losing their High Court challenge against library cuts.
A judge today rejected their claim that decisions to close six "treasured" libraries in Brent, north-west London, were "fundamentally flawed and unlawful".
Local residents fighting the cuts are being backed by celebrities including playwright Alan Bennett, singer Nick Cave and bands Depeche Mode, the Pet Shop Boys and Goldfrapp.
The case is being watched by other campaign groups around the country who also have libraries threatened with closure as cash-squeezed councils seek to reduce spending.
The six facing closure are Kensal Rise, Barham Park, Preston Road and libraries at Neasden, Cricklewood and Tokyngton.
Brent Council says the closures will help to fund improvements to the remaining library service and contribute towards the £104 million of savings it needs to make.
The campaigners accused the council of failing to comply with its statutory duties when it decided in April to close half of its libraries while promising to provide "fewer but better resourced libraries".
Helen Mountfield QC, appearing for the campaigners, argued at the High Court that the council had started from the false premise that library closures were inevitable.
The local authority had failed to comply with equality legislation and consult properly with local people before rejecting the possibility of retaining some or all the libraries through community-based projects, argued Ms Mountfield.
There was inadequate consultation and a failure to assess local needs, including those of ethnic minority groups and children, she argued.
But Mr Justice Ouseley, sitting at London's High Court, ruled there was no evidence to support the serious allegations made against the authority and dismissed the campaigners' application for judicial review.
Asking for permission to apply for permission to appeal, Ms Mountfield said: "This case is important not only for Brent but for other libraries and public authorities generally."
Refusing permission, the judge said: "I do not regard there is any real prospect of success."
Later, campaign group Brent Save Our Six Libraries said they would ask the appeal court itself to hear their case.
Margaret Bailey, a children's nursery manager and one of the leaders of the anti-closure campaign, said: "We are obviously disappointed with the decision given by the judge today. We are determined to appeal if allowed to do so."
The group's solicitor, John Halford, of Bindman's LLP, said: "Today's judgment means that half of Brent's libraries remain under threat and has very troubling implications for library closure decisions nationally."
Brent Council leader Ann John said: "We are pleased that the council has been completely vindicated. The judge, having carefully considered all the complaints, has found in our favour on each and every point.
"It means that we can now push ahead with our exciting plans to improve Brent's library service and offer a 21st-century service for the benefit of all our residents.
"The six libraries we identified for closure were those in unsuitable locations and badly in need of expensive and, quite frankly, unaffordable repairs."
Labour culture spokesman Dan Jarvis said: "Libraries are an important part of local communities, helping to provide vital services to people of all age groups.
"This Tory-led Government has forced councils across the country to make cuts to these important services. Today's judgment has shown that Labour-led Brent Council are making the best of a very bad situation."
Public service trade union Unison said the court verdict should not be taken generally as a "green light" to close services.