Political donations laws in NSW will be tested in the High Court for the first time in a case brought by the union movement, which argues they infringe freedom of political communication and association.

The laws, introduced by the O'Farrell government in 2011, ban donations from anyone other than individuals on the electoral roll and restrict what individual unions affiliated to a political party can spend on campaigns.

Should the laws be allowed to stand, they would "muzzle debate and silence the voice of the working people": Mark Lennon. Credit:Tomasz Machnk

They also prohibit the payment of affiliation fees such as those paid by unions to Labor and restrict the ability of Unions NSW and business or environment groups from receiving money from member organisations to run political advertising.

In documents to be lodged on Monday, lawyers for Unions NSW and five trade unions - including two not affiliated with the ALP - argue the legislation ''interferes with the right of free communication in relation to political matters''. The secretary of Unions NSW, Mark Lennon, said if the laws were allowed to stand they would ''muzzle debate and silence the voice of working people''.