It seems to be happening everywhere, due to budget cuts. Instead of having a qualified teacher covering lessons, now its HLTA'S or cover supervisors.
As a qualified teacher, working as a TA, I've been asked to cover lessons and get paid as a HLTA. I feel offended that I will still get pittance for essentially planning, resourcing, teaching and assessing a mornings work. Also it seems that SLT think so little of children's learning, and the teaching profession that are willing to gave anyone in the class, as long as the lesson is covered.