The information commissioner has criticised the Department of Health for withholding information about the introduction of the MMR vaccine.
The DH redacted relevant details in minutes from three committees involved in the decision to introduce the vaccine, which were later requested under the Freedom of Information Act.
Commissioner Richard Thomas said the DH had taken too long to correspond with the complainant and with his office, made "very generic" arguments for its decisions and gave them too late.
It had claimed that revealing the information would prejudice the effective conduct of public affairs, reveal personal information, compromise commercial interests and compromise health and safety.
A statement said: "The information commissioner's office maintains that disclosing the information will help increase the public understanding of the development of the government's policy on this issue.
"[Mr Thomas] believes that some of the controversy surrounding national immunisation policy has been fuelled by a perceived lack of transparency in the decision-making process which fed into the policy and he believes that there is a public interest in countering this perception.
"Ultimately, knowing who said what and whose opinions were taken into account will facilitate greater openness, accountability and transparency."