The opening of a revamped school for pupils with special educational needs (SEN) in Sussex has been delayed for a third time.
New facilities for Woodlands Meed College in Burgess Hill were originally due to open in time for the autumn term in September.
West Sussex County Council (WSCC) says the site "will not be completed to an acceptable standard" in time to transfer from the old building over the Christmas break.
Woodlands Meed College has been contacted for comment.
Planned new facilities for students aged 14-19 include classrooms, specialist technology and design facilities, a hydrotherapy pool and outdoor learning areas.
The local authority said in a statement: "WSCC is extremely disappointed that despite assurances from the contractor for Woodlands Meed, the main school building will not be completed to an acceptable standard in time to allow the transfer from the old to the new building."
It added that it "shared the frustration of staff, parents and pupils" and was working with the school and contractor to establish a new timeline.
The latest developments come following surveyor inspections of the site last week.
The facilities were due to open in time for the start of term in September, but a further delay later that month meant plans were pushed back to Christmas.
During an inspection in September, governors said they were "gobsmacked" and described the school as "a building site".