Education secretary Gillian Keegan has apologised after expressing frustration for not being thanked for doing a “f**ing good job” during the crisis over unsafe concrete.

The MP for Chichester was recorded on camera claiming others “have been sat on their a**e” following an interview with ITV News.

Ms Keegan had been doing a number of interviews on the ongoing crisis over unsafe concrete in schools across England.

As a camera was being repositioned for extra shots, Ms Keegan said while still wearing her microphone: “Does anyone ever say ‘you know what, you’ve done a f***ing good job because everyone else has sat on their a**e and done nothing?’ No signs of that, no?”

Ms Keegan has since apologised for her comments and said her use of foul language was "unnecessary".

She said: "I am sorry for the language. I didn't mean it at anyone in particular. I was actually frustrated with the interviewer because he was kind of making out it was all my fault."

Downing Street has said that Rishi Sunak has "full confidence" in the education secretary.

It comes after Ms Keegan said that potentially “hundreds more” schools could be affected by reinforced autoclaved aerated concrete (RAAC).

The building material was widely used from the 1950s to the mid-1990s but is now feared to be at risk of collapse.

The Department for Education has so far refused to say which schools are affected, but Ms Keegan told the BBC’s Today Programme that a list of schools would be published later this week.

The education secretary has faced criticism for her handling of the crisis, with one Conservative MP telling Sky News deputy political editor Sam Coates that “she either wasn’t across the detail or didn’t know schools would have to close” during interviews last week.

The unnamed MP also reportedly said: “This investigation on school structures has been going on for a while - I am gobsmacked the advice so quickly and brutally performed a handbrake turn. Keegan needs to be transparent.”

Prime Minister Rishi Sunak insisted that 95 per cent of England’s schools were unaffected by crumbling concrete, leaving open the possibility that more than a thousand could still be impacted by concerns over RAAC.

Pupils in affected schools face being taught in temporary classrooms, on different sites or even forced into pandemic-style remote lessons.

A school in Horsham will be closed tomorrow over fears of RAAC, with an urgent investigation underway at another school in East Sussex.