But it would also play into the hands of the United States, Canada and Argentina, whose suit against the European Union at the World Trade Organisation alleges that EU biotech policy harms trade and is not founded on science.

The EU's 1998-2004 biotech ban, they say, was illegal.

Although the moratorium was lifted last year and two more GMO products have since won EU approval, this has only happened thanks to a legal default process -- not by any consensus between the EU's deeply divided 25 governments.

Now, the political stakes are significantly higher.

The European Commission, the EU executive, wants five countries to lift their bans on certain GMO products, directly challenging their right to prohibit a GMO crop on national territory if they think it is justified to do so.

Between 1997 and 2000, Austria, France, Germany, Greece and Luxembourg banned specific GMOs on their territory, focusing on three maize and two rapeseed types approved shortly before the start of the EU moratorium.

The eight bans -- some countries have blocked more than one product -- mostly relate to cultivation as well as use in animal feed. The Commission says the bans have no justification and wants EU environment ministers, meeting on Friday, to endorse an order for the bans to be scrapped within 20 days.

In at least three cases, the EU executive has already recognised that it is likely to face defeat.

"It's likely that there will be a qualified majority against the Commission proposal," Catherine Day, head of the Commission's environment department, said earlier this week.

She was referring to three bans on Bt-176 maize, a GMO strain made by Swiss agrochemicals giant Syngenta, issued respectively by Austria, Germany and Luxembourg.

But diplomats said the Commission's plan for scrapping some of the other five bans could also be slapped down, depending on the ministers' mood.

"I think there's a good chance that others (orders to lift a ban) may be rejected as well, though the votes at the moment don't suggest that," one EU diplomat said.

"But environment ministers sometimes change their views ... if abstentions became votes against, then some of the other ones could go as well. If there's an anti-GMO mood, then who knows?"

An EU order for a government to lift its national GMO ban could prove extremely unpopular, especially in countries such as Austria where opinion is strongly opposed to biotech foods and there is a strong movement to set up GMO-free zones.

"This vote will be a key test for ministers," said Adrian Bebb at environment group Friends of the Earth Europe.