South Gloucestershire's biggest secondary school has been put into special measures after an inspection by Ofsted.
It's the latest blow to The Ridings' Winterbourne International Academy which saw teachers take strike action in protest against a previous management.
A new leadership team said it accepts Ofsted's findings and was working hard to make improvements.
The Ridings was once considered to be one of the region's best performing schools but Ofsted found it inadequate in three of the five categories.
Inspectors said poor progress in 2015 and 2016 was due to the "wide variability" in the quality of teaching. The school had become "inward-looking", they claimed.
A large budget deficit exists and staff had not benefited from "concerted leadership" for some time.
Dave Baker, the interim chief executive of the trust running the school, said he had expected the outcome for the report and accepted there was not "a clear enough focus" under previous leaders.
There will be "rapid change" at Winterbourne, he added.