SCOTTISH ministers are putting mounting pressure on the UK government to end its support for GM crops now that Wales, Northern Ireland and Scotland have all agreed to become GM-free.

In the wake of the latest GM crop contamination revealed on Friday, the Scottish environment minister, Michael Russell, is urging Whitehall to alter its stance to take account of the strong opposition to genetically modified crops in all the devolved administrations.

His call has been welcomed by anti-GM groups, though they argue he should go further. The GM concordat agreed by the devolved administrations just before the last Scottish election should now be renegotiated, they say.

At a conference in Dublin last week, the agriculture ministers of Northern Ireland and the Republic of Ireland both declared that they wanted their countries to be GM-free. This follows similar commitments from the Scottish and Welsh governments.

"I'm very encouraged by the strong all-Ireland stance that is being taken, and it chimes perfectly with our stance and that of Wales," Russell told the Sunday Herald. "The political dynamic of the GM debate in these islands has changed profoundly over the last year and it is time that the UK government woke up to the fact."

The Department for Environment, Food and Rural Affairs (Defra) in London stressed that it wasn't for or against GM crops. It believed in assessing each application on its merits without blanket approval or rejection.

A Defra spokesman pointed out that the Scottish government was responsible for authorising GM crop trials north of the Border.

Applications for commercial releases, however, were decided by the European Union, where the UK is represented by Defra. "The government is aware of the position of the Scottish Executive sic and discusses these issues regularly," the Defra spokesman said.

Pete Riley from GM Freeze argued that Defra's position was undemocratic. "It's a bit rich for the government in London to override Edinburgh, Cardiff and Belfast," he said.

The GM concordat between the devolved administrations had been negotiated in a hurry early last year between the then Labour administrations to protect the future of GM, Riley alleged. "It was stacked in London's favour, and it should now be renegotiated."

The concordat, dated April 2007, says that "every effort" should be made to arrive at an agreed UK position on GM. But if that failed "the UK negotiating position should be set by the UK government on the basis of expert scientific advice, and taking into account the views of the devolved administrations".

Riley also called for an investigation into how rapeseed planted on three test plots in Aberdeenshire and near Arbroath had come to be contaminated with GM. The Scottish government announced on Friday the contaminated crops would be destroyed.

A batch of conventional rapeseed being grown in trials was found to be contaminated with a genetically modified herbicide-tolerant variety made by the GM giant, Monsanto.

"A risk to the environment would only be present if the plants were allowed to mature and produce pollen and set seed which could spread or persist in the environment," said a Scottish government spokesman.