A LEADING urban conservationist has raised questions over a contract between Edinburgh City Council and a hotel developer over plans for the landmark old Royal High School building.

It comes after the Calton Hill neoclassical masterpiece by Thomas Hamilton, dating from 1829, was the subject of a competition which joint developer Urbanist Hotels and Duddingstonn House Properties won and a conditional lease deal - dependent on issues including gaining planning permission - was set eight years ago.

David Black, author of “All the First Minister's Men”, which told the story behind the construction of the controversial Scottish Parliament building, said the legality of the present contract "may be held to be in doubt", claiming the plan changed from the original winning version.

Urbanist is preparing for a decision next week on its plan as a rival move by St Mary's Music School to take over the old Royal already has approval.

Mr Black said: "This particular lease agreement was the outcome of a competitive selection process, and was originally for a £35 million 'boutique arts hotel'.

"The proposal was substantially modified at a later stage, and the council will now be considering an application for a £75 million 'luxury international hotel' with modern extensions."

He said: "European case law, however, suggests that the legality of the present contract may be held to be in doubt."

He cited cases in Europe where a contract is modified after the award has been made, "to the possible disadvantage of other tenderers. There were more than 50 entrants to the 2009 competition."

Mr Black added: "Given these binding precedents it is is difficult to accept that the contract between the council and its preferred developer is fully compliant with EU regulations, which remain in force until at least 2019.

"Perhaps a reference to the European Court of Justice will clarify the point once and for all."

However, it is unclear whether such a challenge would be successful at this stage.

David Orr, of Urbanist, said earlier that it had adhered to all stipulations of the process, adding "we have taken time to engage with heritage experts and stakeholders to ensure that our plans maintain the historic centrepiece of Thomas Hamilton’s original building and respect the setting by understanding it, accommodating Icomos guidelines in our methodology".

Edinburgh City Council cannot comment on live planning applications.