George Lyon, MSP, whose Argyll and Bute constituency contains many aquaculture businesses, challenged Green Party group leader Robin Harper to clarify his party's position on aquaculture.

Mr Lyon called on the Greens to "distance themselves from the wilder and more extreme members of the Green movement, led by Don Staniford, whose sole objective seems to be the closing down of Scottish aquaculture."

He said it was time for the party to make its position clear on this issue.

This provoked a furious outburst from Mr Harper, who refuted Mr Lyon's "scurrilous remarks".

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