Alan Bennett will tomorrow intervene in the growing row over Chris Grayling's ban on prisoners being sent books.
The celebrated playwright will make his intervention in a newspaper tomorrow with a host of other high-profile authors and leading cultural figures, Politics.co.uk understands.
Bennett's involvement is the latest setback for Grayling as he continues to defend the decision to deny prisoners books received from outside prisons.
It comes as the justice secretary attempts to juggle multiple crises - including the prisoner book ban, a potential tidal wave of compensation claims from inmates and a strike by probation staff.
Grayling has been struggling to justify his policy on banning prisoners being sent books since a comment piece by Howard League for Penal reform chief executive Frances Crook ignited the row on Sunday.
"Let's face it, Grayling has shown his true colours with this policy," shadow justice secretary Sadiq Khan wrote in a comment piece for Politics.co.uk today.
"He's not interested in a rehabilitation revolution. All he's interested in is playing to the gallery and he measures the success of his policies by the column inches he generates.
"Things have now reached such a low that Grayling holds up Oakwood Prison – a jail whose performance was damned by the chief inspector, saying it was easier to get drugs than soap – as his blueprint for the whole estate."
Grayling even appears to be losing the support of fellow Conservatives, with the Daily Mail reporting criticism from normally supportive Tory ministers.
"Chris Grayling wins the prize for the government's least enlightened minister," the unnamed source said.
"He has no backing for this from any quarter at all."
Prisons minister Jeremy Wright refused a head-to-head debate with Mark Haddon, the author of the Curious Incident of the Dog in the Night Time, when the two men appeared on the Today programme this morning to discuss the policy.
"People have got the impression that what we are doing is banning books in cells," Wright told the programme.
"What people can do if they are particularly keen to see a prisoner get a book is they can send the money in for that prisoner and they can get it themselves."
In a comment piece for Politics.co.uk yesterday, Grayling insisted that the incentives scheme which banned parcels being sent to prisons did not curtail prisoners' access to books.
"Wilfully stoking up misconceptions about what were are doing in prisons, and what we are trying to achieve with those changes... doesn't help anyone, least of all those whose offending behaviour it is that we are trying to stop," he wrote.
High profile figures in the literary world, including Cambridge classics professor Mary Beard, children’s author Philip Pullman, novelist Hari Kunzru and poet Ruth Padel have started a petition against the policy, which currently has over 12,000 signatures.
But the justice secretary was barely able to concentrate on the row over prisoners' access to books after the Times published reports that he may be facing a wave of compensation claims by inmates.
The newspaper said he could face a torrent of claims over a backlog of prisoners being held for months, and sometimes even years, after their minimum term.
In one case, a prisoner in Erlestoke prison in Wiltshire has spent seven years in jail, despite only receiving a minimum sentence of seven months.
In total, some 3,500 prisoners have already served a minimum sentence and remain behind bars, costing the prison system £129 million a year.
At the current pace, it will be nine years before the 3,500 are released.
Grayling is also trying to manage several other threats to his position, including an unofficial barrister strike over legal aid cuts, overcrowding in public and private prisons, financial penalties from private sector prison providers, and a strike next week from probation staff in protest at outsourcing.
The Liiberal Democrats refused to disassociate themselves from the policy this afternoon.
"It is utterly untrue to say that we are denying people access to reading material in prisons. We are strong advocates of prisoners being able to read whilst in prison. Education is a vital part of rehabilitating offenders," a spokesperson said.