Campaigners hailed a major victory yesterday after the High Court ruled that Justice Secretary Chris Grayling’s controversial restrictions on prison inmates receiving books from friends and family were unlawful.

Mr Justice Collins’s decision was a victory for Barbara Gordon-Jones, 56, a convicted prisoner serving an indefinite sentence at Send prison near Woking, Surrey.

She challenged the section of the new Prison Service Instruction (PSI) which she said: “imposes substantial restrictions on the ability of prisoners to receive, or have for their use, books.”

The judge said the PSI amended the Incentives and Earned Privileges Scheme (IEP).

He said: “I am satisfied that insofar as it includes books in IEP schemes, the PSI is unlawful.”

The ruling was welcomed by solicitors Lound Mulrenan Jefferies, who acted for Ms Gordon-Jones pro bono along with barristers Jenni Richards QC, Victoria Butler-Cole and Annabel Lee.

In a statement they said: “Reading is a right and not a privilege, to be encouraged and not restricted.

“Indeed, Mr Justice Collins commented that, as far as books are concerned, ‘to refer to them as a privilege is strange.’

“The policy was unnecessary, irrational and counter-productive to rehabilitation. It is now rightly judged unlawful.”

Frances Crook, chief executive of the Howard League for Penal Reform, which launched the Books for Prisoners campaign earlier this year, said she hoped that the Ministry of Justice would “not waste further public money by fighting it in the courts. Ministers should implement this decision immediately so that prisoners can get books for Christmas.”

Jo Glanville, director of writers’ campaign group English PEN, said: “We are delighted at the judgment. This is welcome recognition that books are a necessity and not a privilege.”

She said the government’s “reluctance to address the issue, despite the public outcry and support of leading authors over the past year, has been short-sighted and self-defeating.”

Shadow justice secretary Sadiq Khan said the ban “had nothing to do with punishing and reforming prisoners but was an example of David Cameron’s government’s sloppy policy-making.”