The Information Commissioner is launching a legal challenge over the Transport Secretary's refusal to release a report under the Freedom of Information Act on the proposed high-speed rail network, HS2.
Christopher Graham said he had decided on legal action following the recent Court of Appeal decision in the case brought by Guardian journalist Rob Evans against the Attorney General's refusal to disclose letters written to ministers by the Prince of Wales.
The Evans judgment, although still subject to appeal, states that the exercise of the ministerial veto in respect of environmental information is incompatible with European law.
Cabinet minister Patrick McLoughlin overruled Information Commissioner Christopher Graham's decision that the project assessment report should be disclosed in response to requests under the Freedom of Information Act (FoIA).
The veto, which was imposed in January, prompted anti-HS2 campaigners to accuse the Government of censorship and suggest that the report undermined the case for the project.
Graham has now written to Sir Alan Beith MP, chairman of the Justice Committee, saying he has decided to apply for judicial review.
He told Sir Alan the information in the vetoed review "is all environmental information", and that his June 2013 decision notice requiring the report's disclosure was issued under the Environmental Information Regulations 2004.
"Therefore under UK law as it currently stands, following the Evans case, the Secretary of State's veto of my decision notice was unlawful," Mr Graham wrote.
He said the appropriate course of action was for him to start a legal challenge on the express understanding that it would be stayed pending the outcome of the Attorney General's proposed appeal to the Supreme Court over the Evans decision.
He said he would also seek permission for judicial review on further grounds.
A Government spokesman said: "It's important to strike a balance between the benefits of transparency and protecting the ability of officials to 'speak truth to power'. We have already published project-level data in our annual report of major projects and have no plans to go further."
The Guardian Prince of Wales case has seen more than a quarter of a million pounds of public money pent on legal fees to attempt to block the publication of Prince Charles's letters to ministers.
Ministers will seek to recover all its costs from the Guardian newspaper if it is successful in preventing publication of the letters.
Guardian journalist Rob Evans has been trying to make the letters public under the Freedom of Information Act and in September 2012 a High Court ruled in his favour. The government has been granted permission to appeal against to the Supreme Court.