The headteacher of a Burnley secondary school, that Ofsted inspectors have said "requires improvement" said he has already put measures in place to address the problems.
Mr Richard Varey, who is head of Blessed Trinity RC College said that while he was "disappointed" with the Ofsted report he was determined that the issues highlighted would be sorted out.
He said: “I am proud of the progress the school has made in the last six years, since we were in Special Measures and undersubscribed.
“I have a hard-working and dedicated team here who are determined to improve the outcomes for all pupils, especially the disadvantaged, which we identified and Ofsted confirmed, need to be improved.
“Ofsted highlighted that we are strong in some areas while in others, such as the progress of disadvantaged pupils and lower-ability boys, we are inconsistent and we have already put measures in place to address this.
"I have great faith in my teaching staff.”
The school in Ormerod Road was placed in special measures in 2012 but within two years had turned its fortunes around and was rated as good at its last Ofsted inspection in 2014.
So the latest report, which rated every area as requiring improvement apart from personal development, behaviour and welfare, is a blow as inspectors said that since 2014 the quality of teaching and pupils' outcomes have declined.
Inspectors said this was due to instability in staffing and also because the current curriculum was unsuitable for some groups of pupils.
The report said the quality of teaching across the school was not consistently good and too many teachers set tasks that were too easy for students and accepted work below the standard needed for success in GCSEs, an important point as in 2017 the school had its worst results in four years.
The report said that leaders' actions to improve teaching has not worked because they did not focus on the impact of teaching on the amount of learning and progress pupils were making.
Inspectors also said that while it was improving, the progress that pupils make across many subjects was too variable. They also said that the attendance of disadvantaged pupils and those with special educational needs was still too low.
Personal development, behaviour and welfare was rated as good with Mr Varey and his staff praised for successfully creating a "positive ethos" in the school with pupils' spiritual, moral, social and cultural development described as strong.
Pupils were praised for their good behaviour and conduct and safeguarding arrangements were described as being "thorough and effective."
Children also told inspectors they felt safe, were free from any kind of bullying and there was no racism, homophobia or use of bad language in the school.
Inspectors observed that students' generally had positive attitudes to learning and were grateful for the support they received from teachers.
To improve Blessed Trinity must increase its effectiveness of leadership and management in a range of ways including refining school improvement planning to ensure that priorities, expectations and lines of accountability are clear and focused on improving pupils' outcomes.
Inspectors also want to see robust evaluation of the impact that strategies to improve teaching and learning have on accelerating pupils' progress, particularly for boys and disadvantaged pupils.
The report also called for leaders to ensure that when they make judgements about the quality of teaching they focus more sharply on the progress the pupils are making rather than what the teacher is doing.