Agricultural biotechnology was for a long time defined in the UK as a purely scientific issue. Debate and concern that was not based on scientific evidence was dismissed as irrational, or at best irrelevant (Black 1998), and this narrow framework for decision making went along with a resistance to public involvement. This was very much in line with the UK’s fairly opaque approach to decision making in technical or scientific policy areas more generally. It would, however, have been difficult for such an overtly narrow approach to genetically modified organisms (GMOs) to survive the media and public discussion of the issue in the late 1990s. In the UK as elsewhere, developments in agricultural biotechnology provoked unusual levels of public concern at this time, and major food retailers and processors began to avoid GM produce. Some sort of response was required of government. In 1999, an agreement was reached between government and the industry body, SCIMAC (the Supply Chain Initiative on Modified Agricultural Crops), that there would be no commercial cultivation of GM crops pending completion of certain scientific trials (relating specifically to the impact of the crop management regimes related to four different GM crops on farmland biodiversity). This ‘moratorium’ ran parallel with the EU-wide moratorium on authorisations of GMOs, which the UK government did not formally support. The UK moratorium had an explicitly scientific starting and end point: it was based on concern expressed by, among others, the government’s advisor on biodiversity issues, English Nature, that GM herbicidetolerant crops could have harmful effects on farmland biodiversity,1 and was a temporary decision, pending the completion of further scientific investigation. However, this narrowly scientific ‘precautionary’ stance also created some time for more broadly based public discussion of the issues.