A row has broken out after two conservation groups placed whole-page adverts in Scottish newspapers urging the public to oppose US tycoon Donald Trump's £1bn proposed golf development.

The adverts placed by the RSPB and the Scottish Wildlife Trust appeared in The Herald and The Scotsman, and were paid for by an anonymous donor and Restore UK, a charity which invests in the protection and restoration of Britain's natural habitat.

They said that they are not opposed to golf courses but against a golf course "that needlessly destroys the fragile coastal sand dunes".

The application for the development was the subject of the public local inquiry conducted by James McCulloch, Chief Reporter and Director for Planning and Environmental Appeals.

His report is set to be sent within the next few weeks to John Swinney, Cabinet Secretary for Finance and Sustainable Growth. He has promised to give his decision within 28 days of receiving it.

George Sorial from the Trump Organisation said: "It is an unusual move for two highly respected charitable organisations, created to protect wildlife, to spend so much money on an advertising campaign opposing a development that will ultimately benefit wildlife and the environment.

"It is obviously a desperate final attempt to try to influence government officials and ministers. With so many people commenting on their poor performance during the public local inquiry I am not surprised that they feel it necessary to resort to paid advertising in yet another unfortunate attempt to mislead the public about our project.

"The reporters and ministers should be respected and left to make their decision."

A spokesman for Scottish Wildlife Trust and RSPB Scotland said they received an unsolicited approach from Restore UK.

"Restore UK wanted to fund some action to broaden awareness of this," the spokesman said. "It is curious that Mr Sorial calls for the reporters and ministers to be respected and left alone from distractions' when any noise in opposition to Trump International's application is made, but then chooses to remain silent if any supportive words are uttered."