It started with the helicopter escape from Gartree prison in 1987, followed by the 1991 break-out of two IRA prisoners from Brixton jail and culminated with the Whitemoor and Parkhurst debacles at the end of last year.
Ministers first started looking at the feasibility of a "supermax" jail after Sir John Woodcock's scathing report into the Whitemoor escape, which blamed all levels of the prison service for creating a "disaster waiting to happen".
An American specialist from the US federal system was brought in to advise on security and senior Prison Service staff and Home Office ministers visited the new generation of hi-tech superjails in the US - including one in Minnesota, which while furnished with state-of-the-art security, appears to be built like a Saxon fort - sunk into the landscape with the walls surrounded by artificial hills.
But facing initial Treasury resistance, the plans appeared to be on hold. However, the findings of Sir John Learmont's inquiry into prison security set up in the wake of the Parkhurst and Whitemoor escapes have given them new impetus.
Documents seen by the Independent say that in the absence of public money, it is "crucial" that agreement is secured in principle to private finance. "Early agreement would allow the Home Secretary to accept this aspect of the expected Learmont recommendations ... "
The two stumbling blocks officials foresee are ministers' initial resistance to agree to the plan until seeing both Learmont's findings and the conclusions of a feasibility study - and bad publicity over private sector involvement.
Given that both favour one or two supermax jails, officials are confident of securing ministers' approval "through careful wording of the Home Secretary's briefing". But they say "robust defensive lines of public sector involvement more generally must be available" to head off media criticism.
Although no sites are suggested, draft proposals seen by the Independent suggest the supermax jail will be broken down into small units to hold between 8 and 50 prisoners, each with extensive use of electronic locking and alarms and monitored by closed-circuit television linked to a control room.
Corridors will be similarly secured and each unit will contain "clean" holding cells, for use when searching the unit. There will also be searching facilities at each entry and exit point.
Each unit is likely to have adaptable rooms to cater for whatever activities are in progress, from education to group therapy to work. All exercise yards will be covered by steel mesh to prevent the kind of helicopter escape that took place at Gartree.
Visitors and staff will have to pass through screens, designed to detect, metal, explosives or drugs.
The proposals also suggest that delivery, storage and maintenance departments are all located outside the perimeter wall to make everything easier to search before it enters the prison.
The whole complex will be surrounded by a series of perimeter walls and fences, each with a monitored and alarmed "sterile" area in between.
"Within the constraints of a secure environment the regime will be productive, developmental and prepare prisoners for their eventual release or reclassification," the proposals say.
Where Britain's most dangerous
prisoners are held
Exceptional risk High risk
(eg IRA prisoner) (armed robbers,
Full Sutton 34
Whitemoor 6 37
(Violent and disruptive prisoners)
On assessment in other jails 23Reuse content