By Andrew Porter 7:30AM BST 30 Mar 2011, Published in the Daily Telegraph

Kenneth Clarke, the Justice Secretary, was attempting to head off the confrontation last night and it is understood that David Cameron has been consulted about the threat.

It was unclear last night whether ministers would go ahead with the announcement after the Prison Officers’ Association said it had a mandate from members to strike if prisons were privatised, despite any such action being illegal.

A source Ministry of Justice said: “The unions are very, very angry. They are worried about the market-testing plans and we have had to take note.”

A second government source confirmed: “Obviously, we have contingency plans. Unfortunately, prison officers do represent a strike threat and it would be wrong not to make plans

Published in the Daily Telegraph