An attendance expert says David Seymour's disingenuous to blame attendance numbers on striking teachers. 

He's claiming their industrial action meant term three attendance dropped year on year.

He says it was on track for 52 percent attendance, but ended closer to 50.

Manurewa Attendance Service head Cathy Chalmers says attendance on those days isn't recorded - and numbers usually slip at the end of term.

"Historically, that last day before the long weekend, we get a lot of students not turning up to school."

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