Ken Warman has been replaced as principal at BSix sixth form college by its director of learning Kevin Watson “with immediate effect”.

The move at the flagship college in Kenninghall Road, Upper Clapton – also known as Brooke House – comes two weeks after the publication of a dire Ofsted report.

It was slapped with a “notice to improve” in June.

But 10 months on, inspectors judged every aspect of the college still required improvement – including quality of teaching, behaviour of students and the effectiveness of its leadership and management.

Yesterday it was announced Kevin Watson, director of learning since September, was taking over the helm “with immediate effect”.

Mr Watson, who has 20 years’ experience in “raising standards” as principal at colleges in Leyton, Richmond and Wigan, joined BSix as its director of learning in September.

The same month the government’s sixth form colleges commissioner Peter Mucklow had deemed the college’s position “unsustainable” and found the “unusually” wide range of courses on offer was causing problems at the college which needed to balance its books.

Although in latest Ofsted report conceded managers had taken action and that things were improving, it remained the case that too few pupils are achieving high grade passes, they aren’t achieving functional skills in English and maths, and their attendance and punctuality is poor.

“Governors have not challenged leaders and managers to bring about rapid enough improvements in the quality of teaching, learning and assessment, and student achievements,” they said. “In most subjects, too few students attend regularly enough to make good or better progress in their learning.”

Mr Watson, a central figure in the establishment of the London Sixth Form Partnership – a group of five colleges including BSix, set up to foster cooperation and sharing of expertise – said in a statement: “In my association with the college to date I have seen considerable appetite for improvement and become aware of a widespread readiness to augment the many existing strengths wtih some fresh ideas and new approaches.”

“The aim is to consolidate BSix as the destination of choice for 16- to 19-year-olds.”