American tycoon Donald Trump has vowed to cut the ribbon on his golf resort in Aberdeenshire in 18 months.
He sparked a row after arriving in Scotland on Wednesday by claiming Michael Forbes, who refuses to sell his home to Mr Trump, lived in a "slum".
But Mr Forbes revealed the campaign group Tripping up Trump had bought some of his land in a bid to disrupt Mr Trump's plans.
Mr Trump was spending Thursday meeting the project team, and supporters.
He predicted it would be the best golf course in the world.
Tripping Up Trump has bought an acre of land from Mr Forbes in what it calls the "heartland" of the planned golf resort, and said the development could not go ahead in its current form without access to it.
The group said that by putting the names of hundreds of protesters on the title deeds, it would create a massive legal headache for the Trump Organisation and Aberdeenshire Council if they were to pursue a compulsory purchase order for the site.
The Trump Organisation said the land deal would have no impact on the project.
Mr Trump also said it was "sad" that the property owned by Mr Forbes was a slum.
He added: "It's a slum, I mean it's horrible the way he maintains it. Now, I don't know if he's doing that on purpose, I don't think so, I think just that's the way he maintains his property."
But Mr Forbes said Mr Trump's opinion "meant nothing" to him.
He said: "From where he comes from maybe it is a pigsty. I would never deal with him, he's not worth talking about."
Mr Trump said the total cost of the project was likely to be near £750m, and announced the beach where the course is to be built would be named the Great Dunes of Scotland.
The master plan for the resort will be considered by Aberdeenshire Council later this year.