CANE growers won't breathe a sigh of relief until they see on-supply agreement contracts signed despite the announcement of a "breakthrough”.

With the Proserpine crush expected to begin on July 4, the urgency for QSL and Wilmar to finalise On-Supply and Cane Supply agreements is at boiling point.

Canegrowers Proserpine manager Mike Porter was cautiously optimistic that all hurdles were cleared but said it was important not to jump the gun.

"It's been a very long and hard road for the last three years and we don't want to jump in prematurely and say everything is fine because there may be a couple of other things that need to be sorted,” he said.

"We are asking everyone to sit tight until it is officially signed off so we can get it to the next stage.”

Mr Porter noted Wilmar supplying growers in other parts of Queensland not directly affected by Cyclone Debbie would be likely to begin their crush in mid-June, further increasing the urgency of the situation.

The bitter sugar stoush surrounding grower choice in who markets their sugar caused the LNP state opposition to attempt to force both parties into arbitration.

This was rejected by the Queensland Government, which instead brought Wilmar and QSL into mediation.

Dawson MP George Christensen said the "hovering threat of a Code of Conduct” would have been a contributing factor to the breakthrough. .

"And I also think that growers themselves should be congratulated for holding firm because you can only be forgiven for thinking Wilmar dragged this out so long hoping growers would shrug their shoulders and do what they wanted them to do,” he said.

"I think (Wilmar) realised growers weren't going to budge because the law was on their side.”