[10][13] During his term, Conservative councillors stated their opposition to fracking and called for a moratorium in Ryedale.
[17][18] Duncan was selected by the Conservative Party as its candidate in the May 2024 election for Mayor of York and North Yorkshire.
[19] Duncan took a novel approach to campaigning, carrying out a tour of North Yorkshire, aiming to visit 1,000 communities in 100 days.
[20] His policy of nationalising the Grand Hotel in Scarborough raised concerns over its feasibility, and how conservative the threat of compulsory purchase was.
[21] In response, Duncan claimed that a new Mayoral Development Corporation would be established with the legal powers to seize the hotel from Britannia, then to deliver the necessary private sector investment for the plan to work.