To the animals that will eat it and the corn rootworm beetle that it was bred to resist, the maize known as MON863 looks innocuous enough. But the corn has become the latest potent ingredient in the debate over genetic modification and whether crops that have been altered by scientists should enter the food chain.

For farmers in the Midwest of the United States, the maize represents a breakthrough against a serious pest. For its American producer, Monsanto, the approval granted last month by the European Union for the commercial import of MON863 is a significant step.

It is one of only three new Monsanto products to be allowed into Europe since April last year. For the previous six years, a de facto moratorium had stalled approvals after a strong campaign against GM crops on this side of the Atlantic. The admission of MON863 suggests the process is beginning to tick forward.

For anti-GM campaigners, one more genetically modified organism (GMO) in Europe is one too many. To Greenpeace, the authorisation symbolises everything that is wrong with EU democracy. MON863 was approved by the European Commission on August 8 despite opposition from more than half of the EU’s 25 member states. It is, Greenpeace argues, another example of a genetically modified organism being forced through by the un-elected body.

Genetically modified crops have been around since Monsanto’s scientists successfully altered the genetic material of plant cells for the first time in 1992. Five companies in the world now produce them. Soya bean, corn, cotton and oil seed rape are the most common commercially grown GM crops.

The makers says GM crops pose little risk and have enormous potential benefits. With the ability to grow in environments where others fail, they can literally be used to feed the world. They can be bred to contain more nutrients and to produce better yields, using less water and energy; some require fewer herbicides and pesticides so are better for the environment too.

Opponents say genetic engineering is crude and imprecise, and may trigger unexpected harmful effects in plants or humans. Seeds from GM crops present a serious danger of cross-contamination with conventional and organic crops and could create “superweeds” that are highly resistant to pests. Rather than helping Third World farmers, they say, the wealth produced by GM is concentrated in the hands of too few companies.

Authorisation for GM organisms is dealt with by Brussels because of the trade agreement between EU states. By delegating decision-making powers to the EU, countries become part of the single biggest trading bloc in the world.

In the 1990s, according to Monsanto, the system of approvals for GM products was “relatively straightforward”. But in 1996, with GM crops flowing into European ports, Greenpeace and others began a campaign to raise awareness and to gather support for a ban on their import.

EU legislation since the early 1990s had had two main objectives: to protect human health and the environment, and to ensure the free movement of safe GM products within the EU. Once the Greenpeace campaign gathered steam, opinions in Strasbourg and Brussels hardened against GM. Member states were ready to take on the might of the US.

As public concern mounted over the perceived potential risks, some countries banned certain GM organisms within their own borders . Then at a meeting of the Council of Environment Ministers in 1999, some EU states agreed to block authorisations of any new organisms in Europe until scientific uncertainties were lifted and legislation was improved. Other EU countries and the Commission considered that action to be illegal. They agreed, however, to take a “thoroughly precautionary approach” in dealing with new authorisations and the six-year de facto moratorium began.

Dr Colin Merritt, a spokesman for Monsanto, comments: “Because of the voting procedures of the EU, there is capacity for a blocking group to prevent approvals based not on factual or safety reasons but on political positions.”

In May 2003, the US, Argentina and Canada retaliated against the EU, lodging formal complaints with the World Trade Organisation. The US has used this as a platform to warn other nations tempted to follow Europe’s approach.

There are endless theories as to why such a gulf exists between the US and Europe; Americans have been consuming foods containing GM ingredients for a decade, but Europeans remain sceptical.

“More than 70 per cent of European consumers, including those in eastern Europe, reject GMOs,” says Eric Gall of Greenpeace . “The Commission expected all the new member states to be less concerned about the environment and more pro-USA, but that is not what we’re seeing. Poland and Hungary have already enacted bans on the cultivation of a GM maize to conduct further studies.”

Application and authorisation procedures for GM organisms in Europe are lengthy because of the uniquely complex way the EU works. The system allows states to express their approval or objection to GM organisms - some, such as the Netherlands, Spain and the UK, are considered to be pro-GM; others, including Austria, Greece and Denmark, are vehemently anti. In practice the European Commission controls the process. It has the power to speed it along and to authorise particular GM organisms where disagreement exists between states.

Before decisions are taken, assessments are carried out and opinions are sought from the European Food Safety Authority (EFSA), which was set up in 2002 to provide scientific guidance.

Greenpeace complains that the system is undemocratic and not transparent.“The EFSA dismisses any scientific concerns of national authorities and the Commission effectively over-rules the member states’

objections,” says Mr Gall.

Dr Merritt of Monsanto counters: “Opponents will say the Commission is very pro-GM, but it is an administrative body which makes proposals based on guidelines and test analyses rather than political judgments. .”

Chris Davies, Liberal Democrat MEP for the North West, admits the Commission is walking a tightrope. “The EU is a collective partnership and the Commission acts as an arbiter where member states can’t make up their mind,” he says. “They leave it to the Commission, which becomes everyone’s whipping boy, but someone has to make a decision.”

The European Parliament in Strasbourg is proud of the crucial role it has played in the new legislation introduced last year, especially in relation to demanding a legal framework of traceability for GM organisms and meaningful labelling so consumers can make an informed choice.

With the new legislation in place, the moratorium against GM products was unofficially lifted in April 2004. EU states still have the option of invoking the “safeguard clause” to impose a national ban on a particular product.

Europe’s authorisation procedures are now considered to be among the most rigorous in the world, designed to safeguard human health and the environment.

That neither GM supporters nor opponents are completely in favour of the system suggests it is working as well as it can in dealing with such a complex and controversial issue.