UK Government advisers on genetically modified crops have called for rules to prevent contamination of neighbouring farms if they are widely introduced.
The government is yet to make a decision on GM
The committee, which contains opponents and supporters of GM crops, has agreed guidelines limiting contamination, but some members want a total clampdown.
Fears of ordinary crops being tainted have sparked strong opposition from consumers and organic farmers.
Recent GM crop trials also raised worries over GM's environmental impact.
The committee is considering how GM crops could exist side-by-side with conventional and organic varieties if the government gives the go-ahead for widespread introduction of the technology next year.
But the advisory group, which draws its members from both biotechnology companies and anti-GM lobby groups, is deeply divided on many key issues.
There is agreement that farmers growing GM crops should follow strict guidelines to minimise contamination, but there is no consensus on whether organic farmers' zero-tolerance of GM material should be covered by this.
As farmers are currently unable to insure themselves against accidental contamination from GM crops, there are proposals for a compensation fund - but there is a split on who should be responsible if organic food is tainted.