Oasis Academy’s head teacher has dramatically quit his job at the helm of the Sheppey school.

David Millar, who took up the post as executive principal in September 2013, will be leaving at the end of this academic year.

The news will be a blow to the academy, which has been plagued by years of under-performance, including less than a quarter (24.4%) of pupils gaining five A* to C GCSEs, including English and maths, last year.

In a statement released this afternoon, he said he had been offered a promotion with another multi-academy trust, which is closer to his home and family.

He added: “When I was originally asked to come to Sheppey from Surrey, I committed to doing so for three years.

“I can honestly say that having been here for what will have been two and a half years by the time I leave, that were it not for this great opportunity, I would have committed to staying much longer than I had originally planned.”

Mr Millar has worked with the Oasis Academy network for eight years, having moved from one of its schools in Coulsdon in Croydon.

The school refused to release its grades on national results’ day, citing marking discrepancies and announcing that scores of exam papers would have to be looked at again.

His departure will be the fifth change of leadership since the £54m school was launched in 2009.

No one is yet lined-up to take over from him, with the new executive principle expected to be announced in the coming academic year.

Mr Millar added: “I will be leaving Sheppey with great sadness, but knowing that we have been on a rapid journey of transformation together, and that the values and vision, structures and systems are all in place now to continue the rapid progress that we’ve made.”

Sittingbourne and Sheppey MP Gordon Henderson praised Mr Millar this afternoon, calling him an “inspirational figure”.

He said: “I told him he will be a great loss to Sheppey because his commitment was fantastic.

“But the same management is in place, we are only losing one member of the Oasis team.”

The Tory also said he was reassured the school would be able to find a good replacement and improve further in the future.