A group of kiwifruit growers is urging other growers of the fruit to join them in seeking damages for the Psa virus.

The Kiwifruit claim, representing 45% of the gold industry and 15% of the green industry, is likely to seek damages from the Crown of over $300 million.

There are still growers and others who may have losses of another $400 million, who may not meet tomorrow's court-imposed deadline to take part in the class action.

The Kiwifruit Claim spokesman Mathew Hooton said the government owes them that much, as it was negligent when it let in a shipment of plant goods from a psa-ravaged part of China.

He argues the negligence led directly to the losses claimed.

Matthew Hooton said some growers may not have signed up to seek damages as they may have been misled by initial criticism of the claim.

But now the High Court in Wellington has confirmed it meets all the requirements to proceed as a class action, Mr Hooton said the growers should reconsider.