A Green MSP has called on the Scottish Executive to block the growing of genetically-modified crops.
GM crops have already been grown on a small scale
Patrick Harvie was speaking after the leaking of a document from a cabinet committee in London, apparently indicating that the government will approve the sowing of GM maize.
Until now, modified crops have only been grown on an experimental basis.
But the executive has insisted that no decision has yet been made.
Minutes of a Cabinet committee meeting seen by the BBC suggest that qualified approval for sowing GM maize is imminent.
The Environment Secretary Margaret Beckett was said to have argued that there was no scientific case for a ban.
The minutes outlined plans for a campaign to win over public opinion.
The document said: "Opposition might eventually be worn down by solid, authoritative scientific argument."
But, speaking on Radio Scotland's Good Morning Scotland programme, the Glasgow Green MSP Patrick Harvie said he would be asking his fellow MSPs to support a call for no commercial cultivation of GM crops to take place in Scotland.
He suggested that a legal framework which made the suppliers of modified crops liable for any harm they cause would curb their use.
Campaigners believe the executive should go its own way on GM crops
And he claimed that the government appears ready to ignore popular opposition.
He said: "A decision has been taken that public opinion doesn't matter here."
But the Scottish Executive, while declining to comment on the leaked document, insisted that no decision has yet been taken.
A spokesman said: "The executive, along with other UK administrations, is considering Acre's advice on the farm-scale evaluation crops."
Acre is the independent committee of experts which advises ministers on the issue.
Some researchers have pressed the government to give a positive lead in encouraging the introduction of GM technology.
Professor Vivian Moses of University College London said: "I think the public is often upset by new technology.
"You'll remember people thought pasteurization of milk was the end of the world but in time they came to see that actually this technology, like so many others, is benign and helpful."