However, following a complaint about the alleged “unauthorised” addition and an investigation by Aberdeenshire Council, the sign was deemed a piece of political advertising and subject to planning rules.
Mr Salmond, who now leads fringe independence party Alba, has vowed to challenge this ruling despite it matching the logo of the 2014 referendum Yes campaign and labelled it “pettifogging officialdom”.
Mr Salmond said: “The sign has been up for 18 months since it was carved from driftwood by local Strichen man Mike Morgan.
“It’s a great piece of work and it’s not going anywhere. I have asked the council’s chief executive how much money they have already wasted on this bureaucratic silliness.
“There are issues about freedom of speech but, basically, the council officials should get their priorities right and their facts straight.”
An email from the council’s head of environment and infrastructure services, Paul Macari, states that the sign should have required “advertising consent”.
It states: “No such consent is in place and therefore the sign comprises a breach of planning control.”
What’s more, its location in the curtilage of the B-listed property also means it “impacts on the setting of the listed building”.
Mr Macari adds: “It is considered to have a negative effect on amenity.
“It is our intention to pursue the removal of the sign or seek a formal planning application for its retention.”
Mr Salmond has been warned by the council that he will be forced to take down the sign or lodge a likely to be rejected planning application within a fortnight of local election ballots being cast on May 5.
An Aberdeenshire Council spokeswoman said: “Following a complaint from a member of the public we have assessed the sign in question and advised Mr Salmond that, should he wish to keep the sign, he will require advertisement consent.”