It comes amid a raft of closures prompting campaigns to save the facilities which are seen as vital community hubs.
Parks, sports facilities and museums have also suffered under cuts to town hall culture budgets in Scotland since 2011/12, according to new analysis by Labour.
The number of libraries which closed in Scotland across Scotland last year doubled to 30, leaving a total of 558.
There has been a £22m reduction in spending for libraries over the past six years, the analysis of revenue spending across Scotland shows. The 17.9 per cent cut is higher than the overall 13.9 per cent reduction across cultural services.
A high-profile campaign was launched last year with the support of leading Scottish authors, including Irvine Welsh and Graeme Macrae Burnet, aimed at saving libraries.
But the outlook remains bleak with cuts of £319m earmarked for council revenue budgets next year.
Labour’s culture spokeswoman Claire Baker said: “The SNP government’s decision to pass on Tory austerity to our communities has resulted in multi-million pound cuts to cultural services across Scotland.
“Libraries aren’t just a free source of reading, they are often at the centre of people’s daily lives. They are a place for everyone to learn, to study, to talk and exchange ideas, and can always provide a safe and welcoming environment for vulnerable people in our communities.”
Scotland’s councils have seen more than £500m in total cuts in real terms from their revenue budgets for services like libraries since the start of the decade as the impact of austerity hits home, although it rose slightly last year.
The impact on cultural services has been far-reaching, with more than £5m cut from museums and galleries. Almost £20m has been cut from budgets for sports facilities, while more than £30m was cut from community parks and open spaces.
A total of 69 libraries have closed across Scotland since 2011, according to official figures. This includes 30 in 2017, up from 15 the year before.
Many of the library closures took place in Fife after swingeing plans were unveiled by the council to axe 16 sites as part of a cost-cutting measures. In Scotland, there were 3,515 paid library jobs in 2010 and 3,416 in 2015 – a drop of 99 (3 per cent), a BBC report found.
Sean McNamara, head of CILIP (the Chartered Institute of Library and Information Professionals) in Scotland called for a broader outlook about the benefits of libraries.
He said: “We urge local authorities to recognise the significant short- and long-term benefits of library services to literacy, digital participation, information skills, health and well-being and much more.
“Libraries provide equal access for all and are more popular than both the cinema and professional football in Scotland, providing vital services for Scotland’s communities and they must be supported both nationally and locally.”
The Scottish Library and Information Council (SLIC) has also previously pointed to new investment in library services in recent years. New or refurbished libraries opened in Wick, Grantown, Alford, Denny, Loanhead, Newbattle and Strathaven. Renfrewshire is investing £5m in a new central library in Paisley. East Ayrshire has recently bought a new mobile library fleet.
SLIC chief executive Pamela Tulloch said: “Public libraries are transforming into thriving hubs of community-based activities and continue to attract people of all demographics for various purposes, from reading, job- seeking and health support groups to film screenings, history exhibitions and even dance classes.
“Libraries continue to be the most popular civic resource offered by local government. Visits to public libraries, including online visits, continue to rise and outstrip visits to other leisure and cultural activities,”
The Scottish Government says more than £4.7m has been provided since 2014 to support the development and delivery of Scotland’s first national public library strategy and continue to support innovative ways for people to use public libraries.
Ministers also say overall council funding is increasing by over £200m next year, but this includes budgets for ring-fenced areas, such as childcare, which aren’t part of everyday revenue spending.
“We continue to ensure that our partners in local government receive a fair funding settlement despite further cuts to the Scottish budget from the UK government,” a spokesman said.