The head teacher of a Medway grammar school has stepped down - ahead of an expected critical Ofsted report.

Chatham Grammar School for Boys’ former head teacher David Marshall has not returned for the start of the new school year after retiring, according to a statement published on the school’s website.

The move comes just days before a report from Ofsted is expected to put the school in special measures – if it does, it will be only the second grammar school in Britain to be so.

Less than two weeks ago the Messenger reported rumours that Mr Marshall might not return, but governors declined to confirm or deny.

The new executive principal has been named as Denise Shepherd, executive principal at Rochester Grammar School, while Stuart Gardner, head teacher at the same school, will become interim principal.

In a statement addressed to parents on its website, Ms Shepherd said: “We both look forward to working with staff, pupils and parents.

“Some of my senior staff from Rochester will assist their colleagues from Chatham Grammar School for Boys as we take the school forward into a new era of achievement.

“I am sure you will agree with me when I say that Chatham Grammar School for Boys is a great community school with many promising aspects that we can all work together to build upon, not least the fact that 95 per cent of its pupils achieved five A* to C grade GCSEs including English and maths and the pass rate at A Level was 99.9% in this year’s exam results.”

No one at the school was available for comment.