An interestinf article: http://www.coventrytelegraph.net/news/coventry-news/one-three-coventry-schoolkids-dont-13426052

Unfortunately, this impacts on our own home grown kids. A class can only move at the rate of its slowest learner and not speaking the language has to hold kids back.

Maton can spout all he likes (I actually think he's a prize buffoon) but this is doing Coventry no good at all.

English lessons in modern schools are not what they were . We were taught the real basics-and had to learn-or else.!
Having ethnic pupils in a class is not a barrier to learning correct English-in fact I believe it helps. Teachers have to be more careful.Most ethnic parents expect good teaching and are usually 'on the ball' about sloppy language, appreciating the education their children get.
However-I do believe that ethnic primary children should be assessed before they start school t see if they speak English-many of them don't-and the immigrant parents should be made aware that when they enter this country their children must be able to speak English before they start.
I don't think it will happen though- it will be classed as 'racist','discriminating' or some other such words by the P Ps