Teachers at a secondary school went on strike on Wednesday, claiming that bad management has led to poor pupil behaviour and attainment.
Teachers' union NASUWT said between 37 and 40 teachers from Castle Vale Performing Arts College in Birmingham joined a picket line at the site entrance this morning.
The union said job losses and "inappropriate staff restructuring" at the school have led to behavioural problems with its pupils.
Students in years seven to 10 were told to stay at home while the strike took place, and two more days of industrial action are planned for March 20 and 21.
The school's headteacher said he was "disappointed and disturbed" by the strike, accusing NASUWT of damaging pupils' education, but the union said poor management was undermining efforts by staff to boost students' achievements.
The union has now urged the local authority to launch a formal investigation into the situation at the school.
Chris Keates, General Secretary of the NASUWT union, said: "The Union and its members have made every effort to engage constructively to resolve this dispute but unfortunately neither the school management nor the governors have responded positively.
"Since 2009, when the problems first emerged, there have been endless meetings but no real or sustained progress.
"Pupils and teachers deserve better.
"The teachers at the school now have no choice but to move to strike action.
"They regret the disruption that pupils and parents will face but their action is about securing management practices and a staffing structure that will enable them to focus effectively on teaching and learning.
"They are committed to improving pupil achievement but their efforts are being undermined by poor management practices."
Headteacher Clive Owen said: "I am disappointed and disturbed that the NASUWT union has chosen to damage the education of our children in this way, and this at a time when many students are close to taking their important GCSE examinations.
"We have year 11 students in for lessons that can be run as normal and will use other time to support them with coursework.
"Other year groups have been asked to remain at home for the day. A number of meetings with the union have been held to avoid this."
Keates said: "We are now calling for the local authority to launch a formal investigation into the school and to use its statutory power to issue a warning notice of improvement to the school governing body.
"If the local authority agrees to do this in an appropriate timescale, further strike action can be avoided, the ball is now in its court.
"We feel that the consequences have not been in line with what has been happening. Another teacher has been quoted as saying pupils can get sent home for not having a pencil case but if they swear at a teacher nothing seems to be done about it, and the pupils know what is going on."
Ben Ball, a NASUWT representative who has taught at the school for 32 years, said: "There is a lot of low level disruption and bad behaviour that prevents us from teaching effectively.
He added: "Sometimes you might discipline a child but then you find you're undermined by someone else.
"Wednesday's action emphasises how concerned we are."
A spokesman for Birmingham City Council said: "We have been in dialogue with both sides for an extended period of time and we are looking to set up another meeting between all related parties as soon as possible."