Fairfax has had its freedom of information request for the 2005 surveys refused because they could leave "misleading impressions" about the latest laws, the media company reports.

The government has blocked access to the research on advertising promoting WorkChoices on the grounds that releasing the material is contrary to the public interest.

Although the Department of Workplace Relations says the results can be made public, it insists they remain secret until later in the year, when the election is out of the way, Fairfax reports.