Teachers at a failing Upper Norwood secondary school have voted to strike over what they claim is excessive pressure from senior staff.

Staff at Westwood Girls' College for Languages and Art in Spurgeon Road are to take three days of industrial action in the next month in protest at how often their lessons are observed.

The school was placed on special measures by Ofsted after being rated inadequate in January. 

It has seen a succession of interim managers since June last year and the latest, Christ Everitt, has been monitoring lessons to assess teachers.

Unions NUT and NASUWT say lessons should not be observed more than three times in a 12-month period and that the school has exceeded this, putting teachers under "intolerable" levels of stress.

Graham Cluer, Croydon's national executive member of NASUWT, said: "The pressure this is having on staff is quite serious. 

"Nobody is saying that staff should not be observed and we obviously appreciate that staff need to be accountable - it is part of in-service training.

"But if it gets too much, it actually has a negative effect and we have certainly got to the stage where the amount of lesson observation that is going on isn't helping.  It is not helping improve the quality of teaching - it is actually having the reverse effect.

"It is putting an intolerable workload and stress level on teachers that is detracting from the jobs they are paid for, which is teaching the children."

The strike action, which will take place on May 22, June 6 and June 18, has been condemned by the school's interim headteacher and governors.

Claudine Reid, chair of governors, said: "If leaders in the school cannot observe lessons, they cannot provide relevant feedback or effective support to improve the quality of teaching.

"Enabling teachers to improve their classroom practice is vital for the education of the young people we serve."

She added: "The governing body believes that the school needs to make substantial improvements in order to come out of Special Measures, reverse the fact that we are undersubscribed by local parents, and improve our results which are the lowest of any secondary school in Croydon.

"The students here deserve so much more."

Mr Everitt, who was appointed at Easter, described himself as "saddened" by the industrial action.

He said: “Ofsted judges that the quality of teaching and learning at the school is unsatisfactory and has therefore placed it in special measures.

"Unsatisfactory teaching can be turned around within two or three terms through high-quality support, training and mentoring. Lesson observations are an essential component of this process.

“We worked hard to have the strike action averted and entered into talks with the NUT and NASUWT in good faith, so are saddened by this decision to strike.”

Ms Reid wrote to parents yesterday to inform them of the strike.

Pupils in Year 7, 8 and 9 will all work from home during the industrial action. 

Year 10 pupils will work from home on May 22 but attend classes on the other two days. 

Year 11 students will attend classes on May 22 but only come into school if they have exams on the other days. 

A spokesman for Croydon Council said: “We’re working with the school to see they make arrangements to ensure year 11 pupils in particular are not adversely affected.”

The school will become part of the Harris Federation's chain of academies in September after governors voted in favour of the conversion in December last year. 

Its headteacher, Karen Benton, has been absent since June 2012. The school says she is on sick leave. 

Does your child go to the school? Do you support the strikes? Email chris.baynes@london.newsquest or call 0208 7226351 to give your views.