Genetically-modified crops might turn into weeds by escaping from farms, or by interbreeding with other species.

ECONOMIST: Development and the environment

In the 1990s, I earned my spurs campaigning for public acceptance of genetically-modified crops in the European Union.

FORBES: Global Warming and the English Language

Can there be a meeting of minds between researchers into genetically-modified crops and those who are deeply hostile to the technology?

BBC: GM researcher: 'Please don't destroy our crop'

The BSE episode has made many people distrust science, a distrust which manifests itself now in the entrenched attitudes to genetically-modified crops.

BBC: BSE: lessons for science?

But the one issue above all that sets Labour and the campaigners at each others' throats is the introduction of genetically-modified (GM) crops.

BBC: Blair blasts green pacesetters

In a BBC Wales lecture in February, he spoke in favour of genetically-modified (GM) crops as an important component in future efforts to feed a growing world population.

BBC: Organic farms 'priced out of market'

Making progress on agriculture, particularly on the barriers to genetically modified crops and hormone-treated meat produced by American farmers, will be tough, but is politically important to secure support for the deal in Congress.

WSJ: Bartering Over a Trans-Atlantic Trade Deal

Environmentalists had argued that there might be a risk of cross-pollination between genetically modified plants and neighbouring crops.

BBC: Monsanto GM seed ban is overturned by US Supreme Court

This is especially important because some experts think the next wave of genetically modified crops may come from government-funded labs as well as industry ones.

FORBES: C'mon, Forbes Wasn't Entirely Wrong About Monsanto