The Government has vetoed a ruling that it should publish one of the risk registers drawn up for the latest NHS overhaul and reform.

In March, an Information Tribunal rejected an appeal from the Department of Health against an order from the Information Commissioner’s Office to publish the transition risk register, which focuses on the threats posed by the reforms.

It said the government could keep secret a second register; the strategic risk register, which covers ongoing threats to the service.

However, the Cabinet has now blocked the release of the transition register.

Health Secretary Andrew Lansley said he was a firm believer in transparency and he did not take this “exceptional” step lightly.

“But there also needs to be safe space where officials are able to give ministers full and frank advice in developing policies and programmes," a statement said.

"The Freedom of Information Act always contemplated such a ‘safe space’ and I believe effective government requires it.”

“That is why cabinet has today decided to veto the release of the department’s transition risk register.

“Had we not taken this decision, it is highly likely that future sensitive risk registers would turn into anodyne documents, and be worded quite differently with civil servants worrying about how they sound to the public rather than giving ministers frank policy advice."

Top officials from the Cabinet Office and the DH had argued that releasing the register would have an “insidious” effect on the work of officials and the advice given to ministers.

A Department of Health statement said that in light of the interest in this case, it has published a document that sets out key information relating to the areas of risks in the original Risk Register.

An ICO spokesperson said it would need to study the Secretary of State’s statement of reasons for imposing the ministerial veto in this case.

“These must, under the criteria established by the government, be ‘exceptional’,” the spokesperson said.

“We will present the Commissioner’s formal report on the matter to Parliament next week.”