Thousands of pupils have been taught by unqualified teachers due to recruitment problems and a shortage of fully trained supply teachers.

Demand for temporary teachers has exploded since the pandemic but a fifth of those being used do not have qualified teacher status, an official inquiry has revealed.

A Sunday Express probe identified recruitment agencies advertising supply teacher posts with a promise that qualifications are not necessary.

The Department for Education now says it is spending £233million to recruit 6,500 more expert teachers - after schools in England spent £521million on agency staff last year, up from £485million in the 2019-20 academic year.

We discovered an agency advertising a vacancy for "Unqualified Supply Teacher" for a southwestern school with a "likely duration" of a year.

Another recruitment site invited applicants for roles as "unqualified cover teachers (no previous experience required) who are able to take some of the responsibility of the full-time class teacher" in case of absences.

And a third agency stated on its site that qualified teacher status (QTS) is "a preferred requirement for becoming a supply teacher" but added: "It is important to note that there are alternative routes to becoming a supply teacher, even without QTS."

The Government's social research unit found schools increased the use of supply teachers after the pandemic, meaning they ran classrooms for "a few hours to several weeks or even months".

It said in a report: "The drivers of this growth are increases in the number and duration of teacher absences and recruitment difficulties."

But the inquiry found around eight in 10 were qualified, with the other 20% not. In addition, just 64% had held a permanent teaching position. It said: "Of the supply teachers surveyed, around a fifth did not have QTS. Most leaders report occasions when they have had to accept non-specialists or supply workers without QTS to cover absences, particularly at short notice."

Local councils used to provide schools with temporary staff when needed but they now usually come from private agencies, which can charge schools £2 for every £1 paid to the teacher.

This has "a significant impact" on budgets, with heads scrimping on permanent staff's training to try to balance the books, the DFE found.

The unit's spokesman said: "Recruiting and keeping high-quality teachers in classrooms is the single biggest driver of high standards in schools.

"We are committed to resetting the relationship with the education workforce and working alongside them to re-establish teaching as an attractive, expert profession."

A House of Commons inquiry last year warned of particular shortages in the recruitment of music, physics, foreign language and computing teachers.

'Around a fifth did not have qualified status'