A parliamentary inquiry into milk prices is looking more likely after Agriculture Minister David Carter said there would be "some value" in such a probe ahead of a decision tomorrow on whether it will take place.
Labour and the Greens have been pushing for a select committee inquiry after the Commerce Commission last week decided not to stage a formal investigation into milk prices.
Giant dairy co-operative Fonterra still faces several other probes, including one into alleged abuse of market powers and an inter-departmental review of its raw milk price.
If the National caucus does not back an inquiry, it may go ahead anyway. Act MP Hilary Calvert, who holds the balance of power on the commerce select committee, which would conduct the inquiry, has indicated she would support it if issues around dairy giant Fonterra's ability to set factory and farm gate prices were examined.
Act's caucus will also decide whether to back the inquiry tomorrow.