It is difficult to tell what percentage of these 'unqualified' teachers might be due to teacher shortage (maths, physics etc.), downgrading or 'new roles' in teaching.
Looking at some of the job adverts for 'unqualified' teaching posts, quite a few are for PE or sports teaching. Has PE teaching been downgraded or are there more sports teaching jobs available in schools due to extra funding? Certainly, some of the jobs advertised are for primary schools and this is surely due to the extra sports funding available since 2012 (average extra funding is £9,000 pa per school).
It would be considered a luxury to have a PE teacher with QTS in a state primary school who only taught PE. The same can be said of 'specialised' language teachers in primary schools which also seems to be increasing. Also, dedicated 'pastoral care' teachers in secondary schools - is that a relatively new role?
I looked at 2 'random', 'outstanding' primary schools in London:
Rosendale Primary, an academy in SE21 which has 'specialist teachers' in Mandarin (2 full time Mandarin teachers), French, PE, Sport and Fitness, Welfare and Forest School plus an Artist in Residence.
Pimlico Primary, a free school which was criticised before it opened in 2013 for planning to employ 'unqualified' teachers, attained an 'outstanding' Ofsted within 2 years and has 'specialist' teachers for History, Computing, French, Music, Art and Geography.
Are these 'teachers' counted in the stats?