Leading authors will gather at Downing Street today (Friday 27 June) to urge David Cameron to overturn restrictions on sending books and other essentials to prisoners.
Writers including Sir David Hare, Mark Haddon, Sarah Waters, AL Kennedy and Kathy Lette are to join the Howard League for Penal Reform and English PEN for the event, organised as part of the Books For Prisoners campaign.
They will present to Number 10 a letter signed by more than 40 high-profile figures  including Poet Laureate Carol Ann Duffy, Alan Bennett, Salman Rushdie, Philip Pullman, Vanessa Redgrave, Julian Barnes, Irvine Welsh, Jacqueline Wilson and Joanne Harris.
"We believe this is a misguided policy," the letter states. "Reading goes hand in hand with education and rehabilitation, whilst research shows that informal learning reduces reoffending… We strongly urge you to reverse this harmful policy at the earliest opportunity."
The campaign is calling on the government to end restrictions, introduced in November 2013, which prevent families and friends sending books, underwear and other essentials to prisoners.
Tens of thousands of people have shown their support by signing a petition and sending photographs of bookshelves to the Ministry of Justice's Twitter account using the hashtags "#shelfie" and "#booksforprisoners". The government's stance has also been condemned by international writers and former prisoners of conscience.
The gathering at Downing Street was organised after Justice Secretary Chris Grayling refused to meet the Poet Laureate and other writers to hear their concerns.
Frances Crook, Chief Executive of the Howard League for Penal Reform, said:
"The Justice Secretary's refusal to meet with us to discuss the issue has succeeded only in galvanising the campaign and baffling anyone who believes we should be broadening access to reading and not restricting it.
"This is a petty and counter-productive policy which the Ministry of Justice has tried and failed to justify with spurious arguments.
"It is surely time the government conceded a change, particularly against a backdrop of ever more overcrowding, growing unrest in prison and an alarming rise in suicides behind bars."
Jo Glanville, Director of English PEN said:
"We're dismayed by the Justice Secretary's failure to respond to an unprecedented public campaign. We're hopeful that David Cameron will appreciate the necessity of reversing a misguided policy.
"There is already evidence of the positive and lasting benefits of access to books on prisoners. At a time of chronic overcrowding and stress in the prison population, it would be perverse to continue to deny supporting the enjoyment of a fundamental human right."
Date: Friday 27 June 2014
Time: 12.00pm to 12.30pm
Venue: Richmond Terrace (opposite Downing Street, on Whitehall), London, SW1A 2JL