In truth the GM trials, whose results will be reported on Thursday, were always more political than scientific. And their impact - despite being the biggest experiments of their kind conducted anywhere in the world - will be felt most in Whitehall, Westminster and the often disconcertingly plush offices of the big environmental pressure groups.

Their establishment, in 1999, was a political act. Michael Meacher, the then environment minister who was already developing doubts about the technology, pulled off a remarkably skilful coup in getting all sides to agree to them and thus postpone the introduction of commercial GM crops until the results were in.

At the time, several modified crops were ready to be grown in Britain and Tony Blair would have been happy to give them the go-ahead. But English Nature, the Government's wildlife watchdog, was raising concerns about their effects on the environment. And a furious public row was mounting with several newspapers - led by The Independent on Sunday - campaigning for a delay...