A Federal Court judge has labelled a Fair Work lawsuit against the CFMEU and a number of its officers an "an abuse of process".

Justice Darryl Rangiah ruled the case, which related to the shutdown of two Brisbane construction sites in 2013, was “unjustifiably vexatious and oppressive”, because the union had previously reached a settlement with the construction company behind the projects.

Fair Work filed an application seeking to impose fines in relation to the industrial action, claiming the CFMEU and 21 of its officers broke the law 822 times during the 97 days the sites were shut down.

Union lawyers have opposed the lawsuit from the outset, claiming there was “no reasonable prospect of successfully prosecuting” their clients.

Their argument was based on a “significant overlap” between the current proceedings and a previous court action involving John Holland contractors and four CFMEU staffers, that was settled and discontinued.

Justice Rangiah said Fair Work’s decision to prosecute the four people involved in the previous action, including the union’s Queensland assistant secretary Jade Ingham, was “unjustifiably vexatious and oppressive” to the people who were also involved in the earlier lawsuit.

However, he did not consider the proceedings relating to the 17 other people problematic.

Justice Rangiah said he required further submissions from both parties to determine “to what extent” the lawsuit was an abuse of process in relation to the four union members.