Chris Grayling to unveil plans for Britain's biggest prison Some 84,000 inmates were behind bars last Friday, down slightly from the all-time high of 88,179 at the end of 2011 in the wake of the summer's riots. But official projections from the Ministry of Justice show the population could rise as high as 90,900 in the next five years. Sites being considered for the super-jail, which would hold around 2,000 inmates, are understood to be in London and the North West or North Wales. But the plans will cause concerns for prison governors and penal reform groups who claim large prisons are difficult to control and would result in inmates being "warehoused." Britain's current largest jail, the Victorian Wandsworth Prison in south London, can hold up to 1,665 prisoners while the new Oakwood Prison in Featherstone near Wolverhampton, run by G4S, opened last year with places for up to 1,605 prisoners. The latest inspection of the Wandsworth jail raised serious concerns over the safety of prisoners, adding there was "no doubt it holds a challenging population with multiple problems." Plans to build Britain's biggest jail will also evoke memories of Labour's £2.9 billion proposal for three 2,500-capacity Titan jails, which was scrapped in 2009 with Jack Straw, the then-justice secretary, saying critics believed the advantages were far outweighed by the disadvantages. Dominic Grieve QC, who was then the shadow justice secretary but is now the Attorney General, said at the time that the u-turn was a nail in the coffin for the flawed approach of using "giant warehouses" as prisons. Juliet Lyon, director of the Prison Reform Trust, said with crime levels falling "the only reason to revive the debunked idea of Titan prisons would be for political capital." "Toughness is not the same as effectiveness," she said. It would be a gigantic mistake if the Justice Secretary were to pour taxpayers' money down the prison building drain.