Australian Trade Minister Craig Emerson again has warned MPs a move to prevent the import of New Zealand apples is in breach of world trade rules.
Opposition agriculture spokesman John Cobb planned to introduce a private bill to parliament today that aimed to overturn an import clearance by Australia's biosecurity and quarantine authorities.
Dr Emerson demanded that Opposition Leader Tony Abbott quash the move which he said flouted a decision of the World Trade Organisation.
"If he supports the bill or sends it off to committee, Mr Abbott will cement in place his anti-trade, isolationist credentials," he said in a statement.
Parliamentary approval of the bill would put Australia in breach of the world trading rules, inviting retaliation against innocent Australian farmers, Dr Emerson said.
Australia banned imports of New Zealand pipfruit or trees for over 90 years, after fireblight was found in Northland in 1919.
In recent decades, growers used as a non-tariff trade barrier allegations that New Zealand apples could spread fireblight, but failed to scientificaly substantiate their case at WTO hearings. New Zealand attempts to access the Australian market failed in 1986, 1989, and 1995.
But New Zealand scientists produced evidence at the WTO that fireblight bacteria are not transferred on clean, ripe fruit and argued that mature symptomless fruit posed no risk of infection.
A WTO panel found 16 scientific inconsistencies in quarantine measures sought by Australia, and the trade body ruled in November last year that Australia should remove import restrictions on Kiwi apples.
Australian Prime Minister Julia Gillard later said her Government "accepts the verdict of the global umpire and will implement the World Trade Organisation rulings on the importation of New Zealand apples".
But a Liberal senator in Canberra, Bill Heffernan has previously criticised biosecurity assessments which he interpreted as saying: "We're going to bring fireblight into Australia but it's not going to get into our paddocks".
Senator Heffernan said:
"We're going to feel it, we're going to go to war on it.
"Bugger the WTO."
Meanwhile, the small state of Tasmania is attempting to maintain its import restrictions on New Zealand apples.
"We will be exploring all of our powers to protect the biosecurity of Tasmania," Tasmanian Premier Lara Giddings said. "We have a very strong border protection system here in terms of biosecurity, helped by our island status. We believe it's worth protecting, not just for Tasmania's sake, but for Australia's sake."
Australian food law expert Joe Lederman of the FoodLegal firm has predicted that the proposed ban could create a constitutional aw test case for the High Court of Australia if the Tasmanian government persisted with its ban.
Lederman said: "There are Constitutional Law difficulties for a state to maintain a ban if it contravenes WTO treaty obligations to which the Australian government is a signatory.
And Australian growers on the mainlain are marketing locally-grown apples with an Aussie Apples sticker. The aim of the campaign is to make it easier for consumers to identify and buy Australian-grown apples in supermarkets or greengrocers.