The contaminated oil seed rape is believed to have been sown in thousands of hectares of land in Scotland.

Jim Walker: "Show leadership"

At a food conference in Edinburgh, Mr Walker dismissed as "ridiculous" suggestions it was for farmers themselves to take the seed company to court.

"Even if we win a court case, even if we had the funds to pursue it, when and where would it be resolved?

"Probably in years in the European Court - and meanwhile innocent growers lose out," he said.

"It is the least he (Nick Brown) can do after weeks of Ministry of Agriculture, Fisheries and Food (Maff) dithering and incompetence.

"If he will not, then the Scottish Executive must - and show some strong, truly devolved leadership."

'Lack of judgement'

Mr Walker said Maff had shown a "total lack of judgement" from the start but could have been advised of the implications if it had told agriculture colleagues in Scotland, and had sought input from farmers' representatives.

"Quite simply, we wouldn't be in this mess. Seed would have remained in the bag and been returned to merchants and alternative seed or crops would have been sown in April," said Mr Walker.

The row over the oil seed rape contamination took a fresh twist last week when Mr Finnie disclosed it had taken the London ministry a month to alert him to the contaminated seed.

Advanta supplied the contaminated seeds

So far the UK Government's stance has been that losses incurred by farmers are a matter to be resolved between the farmers and their seed suppliers.

Under EU rules, the GM crops produced from the seed cannot be marketed within Europe.

Mr Walker said: "The final irony is the suggestion that innocent growers who grow the crop to harvest, could be liable for prosecution themselves if they attempt to sell this crop, as the GM seed is only licensed for field trials and not for commercial production."

He added: "This failure of communication from London to Edinburgh is not an isolated incident.

"It has to be addressed urgently if joined-up government is to work and not just be a hollow soundbite."