Strasbourg - Green members of the European Parliament stood en masse and held up placards on Tuesday in protest against the EU Commission approval of the cultivation of genetically modified potatoes.
The deputies help up placards that read "For a GMO free Europe" as one of their number, Rebecca Harms, berated European Commission chief Jose Manuel Barroso for last week's decision.
German MEP Harms called it a "risky strategy that will not find support" among EU citizens.
"There is no reason to authorise this GMO potato, we don't need it," she said in the protest during question-time in the parliament.
Barroso congratulated the Greens for their "enthusiasm".
"You have a position very strongly against GMOs, that is your right," he said, sometimes shouting over the howls of protest.
He said he had "no prejudice in favour or against GMOs" and merely took advice on their safety from the European Food Safety Agency.
The commission last week approved the cultivation of the Amflora potato, developed by German chemical giant BASF, for industrial use in paper making but not for human consumption.
Modified vegetables and cereals, so-called "Frankenfoods", have long been a matter of fierce debate in Europe.
Some genetically modified products have been approved for sale in Europe but before the BASF potato only MON 810, a strain of genetically modified maize made by Monsanto, had been authorised for cultivation.
The EU's food safety agency has said the Amflora potato, designed to produce industrial starch, is safe for all uses.
But the potato contains a marker gene which is resistant to antibiotics, fuelling fears over the risks of contamination for conventional varieties.
Greenpeace has said the decision to allow the potato to be grown in Europe was shocking and "puts the environment and public health at risk".
Barroso recognised that "there are deep differences among our member states" on the GMO issue.
Where there is no majority, his commission, the EU's executive arm, is authorised to take the decision itself and it had decided "unanimously" to approve its cultivation, he said.
"We believe all scientific issues have been fully addressed," he added.
At the same time he said the intention was to give individual EU nations a choice on whether to cultivate authorised GMOs on their soil.
At present governments must give a reason for blocking the growing of such crops.
Six nations - Austria, France, Germany, Greece, Hungary and Luxembourg - have banned the planting of the MON 810 maize. - AFP