I was disappointed that the TESpro debate on ability group teaching did not seem to want to discuss why successive governments have supported teaching in ability groups (“Do setting and streaming work?”, 29 March).

A member of the present government has pointed out that only one vote in 60 affects the outcome of a general election - and that these voters tend to be middle class and middle ground. This means that governments make the political judgement that the “parents who matter” are the sort who don’t want to see their middle-class child in the same teaching group as some low-ability, working-class child who may have a behavioural problem. The solution is for these low-ability students to be separated. This means that, despite research that tends to suggest that mixed-ability grouping is generally more successful than grouping by ability, we are given the impression that setting beats all.

Mike Rath, Barnstaple.