The headteacher of Acland Burghley School has resigned months after the school was heavily criticised by Ofsted inspectors.

Jo Armitage will step down in September following three years in the role at the Tufnell Park school.

John Clark, the interim chairman of governors at Acland Burghley, said last night she decided to resign from the post as “a signal of the school’s commitment to make the significant changes required to sustain improvement.”

“Jo Armitage has made a significant personal contribution to Acland Burghley over the past three years, and the governors are grateful for the leadership that she has brought to the school,” he said.

“Jo’s decision to act in the best long term interests of the school is a courageous one that will help ensure that the school remains a vibrant community comprehensive school.”

Acland Burghley School, in Burghley Road, was downgraded from a “good” school to “requires improvement”, one above the lowest rating, in an Ofsted inspection report published in October.

It was slammed for its high number of exclusions, slow progress of students and its teaching.

During her time at Acland Burghley, Jo Armitage banned all fizzy drinks, oversaw the opening of an autism resource centre and had to send pupils home early in 2010 when students planned to occupy the school as part of a protest against tuition fee rises.

The governors will now take steps to appoint Ms Armitage’s successor.