Jeremy Corbyn has given his full backing to campaigners and trade unionists who plan to march against Tory cuts to libraries across the country this weekend.

Saturday’s demonstration comes at a critical point for many libraries, galleries and museums, with BBC figures suggesting that over a quarter of library staff have lost their jobs and 343 libraries closed since 2010. Volunteers are being used to plug gaps more and more, with numbers already doubling under the coalition government.

Conservative run councils in Westminster and Kensington and Chelsea have proposed to axe all libraries, which follows Bromley’s attempts to sell off and privatise its libraries.

In Barnet, the council isn’t closing the libraries, but is forcing out paid employees only to replace them with volunteers. This follows the pattern seen across the country, with Doncaster Council running “community libraries” where the buildings and books are provided by the council but all the staff volunteers, as a result of Conservative policies that Corbyn says “have devastated our public services”.

The Museum Association surveyed galleries and museums on cuts, which showed a 24 per cent decrease in staff numbers in 2015 with 18 per cent of respondents reporting that part of their museum had been closed to the public in the past year. Many visitor services are also being privatised.

Thousands are expected to attend the march, which will begin at the iconic British Library and end with a rally outside the National Gallery at Trafalgar Square.

“I give my 100 per cent support to this demonstration,” Corbyn said.

He added: “The Tories have devastated our public services using austerity policies as justification. I promise that a Labour Government will act to ‘in-source’ our public and local council services and increase access to leisure, arts and sports across the country. We will reverse the damage the Tories have done to our communities in the cities, towns and villages.”

Unite national officer Fiona Farmer said: “Tory government cuts to local government funding have wrought havoc to our public libraries with hundreds closing and councils like Westminster seeking to axe all librarians with no public consultation.”

“What we are seeing community by community is an act of cultural and educational vandalism. Libraries are the gateway to knowledge, learning and enjoyment for all ages of people from all walks of life. Yet more and more communities are seeing their library disappear or service diminish because of librarian cuts or failed privatisation.”

“The demonstration in London will be an opportunity to say to the government hands off our libraries and to councils like Westminster to drop their callous plans to axe librarians with masses of expertise.”

Public and Commercial Services (PCS) union general secretary Mark Serwotka said: “Given the clear benefits arts and culture bring to our society and our economy, cuts to libraries, museums and galleries represent everything wrong with the Tories’ approach to public spending.

“While institutions are closing, privatising services or charging for access, the staff who guard our nation’s cultural treasures are languishing on low pay and insecure contracts.”