Plans to turn the Old Royal High School building in Edinburgh into a luxury hotel are facing rejection.

Developers have proposed turning the A-listed building on Calton Hill into a 127-room hotel.

Council planning officials have now said it would harm the historic nature of the site and the landscape of the city.

They have recommended that councillors turn down the hotel plans when they meet next week.

A rival plan to turn the iconic building into a music school has been approved in principle but developers behind it currently have no rights to the building.

In their report, Edinburgh planning officials said the 19th-century neoclassical building was an "architectural masterpiece".

The hotel, which was scaled down from previous proposals, failed to provide the "world-class" designs the site needed, they said.

Planners objected to two new five-storey bedroom wings on the grounds, which they said would interfere with the building's historic character.

The hotel would have required the demolition of the entrance lodge and gym, which the officials said could not be justified.

The report said: "The former Royal High School is an architectural masterpiece and one of the most significant buildings in Scotland.

"The proposed wings would have a significant adverse impact on the composition, integrity and special character of the listed building.

"The benefits to the city's economy and to tourism through bringing an 'at-risk' building back into a sustainable long-term use are not outweighed by the very significant harm to the built heritage and landscape of the city.

"The development would cause permanent and irreversible damage."

Developer Duddingston House Properties and Urbanist Group, which has a long-term lease for the council-owned building, submitted the scaled-down proposals after an initial £75m plan for a 147-bedroom hotel was turned down in 2015.

It argued the revised plans respected the site's historic status and would breathe new life into the Calton Hill area.

David Orr, chairman of Urbanist Hotels, said: "Our design will restore and regenerate this national treasure with a new use as a world-class hotel for the people of Edinburgh and beyond.

"Heritage and conservation are central to our plans.

"This is the only proposal that can realistically guarantee the future of the building - both architecturally and financially.

"Without it, we risk another 50 years of disrepair and misuse, which would be catastrophic for both the building and the city."

He continued: "I am confident that those who genuinely care about Edinburgh's future, and can look through the emotional rhetoric and see the hard facts, won't let this happen."

Negotiations to develop the historic building have been under way since 2009 but groups including Historic Scotland opposed the development.