Referendum campaign signs in fields along the A75 have been destroyed this week with Yes campaign stickers left at the scene.
Galloway and West Dumfries MSP Alex Fergusson said it showed no respect for the rights of the voters or freedom of speech.
He said:“I fully accept that this referendum campaign is a campaign like no other, but that makes it all the more important to respect the right of those on both sides of the argument to highlight their views in any legitimate manner that they choose.
“The erection of large field posters across the region giving the simple ‘No Thanks’ message is a perfectly legitimate campaigning tool – many people clearly think so, because the demand to display these posters has now exceeded the supply of them.
“However, many of the posters put up over the last few weeks were ripped down or smashed to pieces by vandals who, in most cases, left ‘Yes’ stickers behind. No doubt they look on this as just part of the game, although this referendum is far too serious to be looked upon as any kind of game.
“The more serious side of this type of illegal activity is its total defiance of the right to freedom of speech – the most fundamental right of all.
“Couple that with the totally illegal but widespread use of council signs to display ‘Yes’ stickers, and you have a picture of a campaign that has no regard for either the law or the right to freedom of speech.
“All right-minded people should ask themselves if that is the sort of society they want to encourage as they go to the polls next Thursday.”