In a letter published by the Scotsman, Association Chairman Tim Jackson questions the First Minster's understanding of what is crucial to ensure a sound economy and the future prosperity of Scotland.
"Sir, The National Farmers’ Union in Scotland has given Theresa May’s Brexit deal their backing, saying that it will allow continued strong trade in agricultural goods and in Scotland’s food and drink industry.
"In addition to the support of the Scottish Fishermen’s Federation and the support of the business community for the Prime Minister’s deal, it means that three of the largest business contributors to, and drivers of, Scotland’s economy are in support of the deal.
"Nicola Sturgeon’s outright opposition to the Prime Minister’s deal therefore shows scant regard and understanding of what is crucial to ensure a sound economy and the future prosperity of Scotland.
"Yours etc, Tim Jackson"