Ministers face a grilling from MPs today over claims they are planning to downgrade Freedom of Information laws.
Cabinet Office minister Francis Maude, Attorney General Dominic Grieve and justice minister Lord McNally are due to appear before the Justice Select Committee.
Information Commissioner Christopher Graham lashed out yesterday over the Government's decision to veto publication of a report into the risks of NHS reforms, despite a tribunal ruling that it should be released.
Graham dismissed suggestions that the principle of privacy in policymaking at stake.
"The arguments are deployed in support of what is, in fact, the direct opposite of the exceptional - a generally less qualified, and therefore more predictable, 'safe space'," he wrote.
"As such, the Government's approach in this matter appears to have most to do with how the law might be changed to apply differently in future."
The November 2010 Transition Risk Register set out internal Government assessments of the risks posed by the reforms in the Health and Social Care Act, which became law in March after a tortuous passage through Parliament.
Ministerial vetos have previously been used to prevent records of Cabinet discussions being made public.
Former Cabinet Secretary Lord O'Donnell has suggested that FOI should be curbed to protect the ability of politicians and civil servants to speak freely when formulating policies. Tony Blair has also indicated regrets over introducing the Act.
However, supporters point to major scandals such as abuse of MPs expenses which may never have emerged without it.