One of those older farmers, standing with his daughter and son-in-law in the bitter cold, was Sir John Kemp-Welch, 88, who owns 5,000 acres of "difficult hill farming land" in Perthshire where he and his children farm blackface sheep.
"It's not easy," he said. "Farming in Scotland is very tough but we are determined to go on."
Kemp-Welch said an inheritance tax bill would be "very expensive and possibly fatal. It will all go to my children and they will suffer."
"It would probably take all my children's lives to pay off the inheritance tax bill," he said.