International students have been offered casual employment at just $50 per day, well less than half the Australian minimum wage, to campaign on behalf of a Liberal National Party councillor in the lead-up to Saturday's poll.

Workers manning prepoll booths for Macgregor councillor Steven Huang's campaign have been paid $50 a day for what was advertised as eight hours' casual work.

The arrangement angered Queensland Council of Union assistant general secretary Michael Clifford, who said it raised "further concerns" about the LNP's attitude towards workers.

A post seeking workers for the LNP campaign was sent to members of UQ Focus, a group for Christian international students at the University of Queensland with a high proportion of Chinese-speaking members.