MPs on Parliament's commerce select committee will discuss whether they should hold an inquiry into milk pricing when they meet on Thursday.
The Labour and Green parties want the committee to investigate the matter after the Commerce Commission announced on Tuesday that there is no basis for a full inquiry into whether there should be price controls for retail and wholesale milk.
Following a review, the commission decided there is enough competition at retail and wholesale levels to more than meet the requirements of the Commerce Act.
The Green Party's consumer affairs spokesperson, Sue Kedgley, is concerned Government MPs on the committee will block an inquiry, putting the issue on the backburner before the election on 26 November.
But Labour's commerce spokesperson Lianne Dalziel, who chairs the committee, hopes an agreement will be reached by MPs to hold an inquiry into at least some aspects of milk pricing, given the public interest.