Power Line's John Hinderaker isn't ambivalent about teachers unions, see his opinion thereof.
In America, teachers’ unions are the most malign influence on our public life, and on our children. And they aren’t any better in Great Britain.
His column goes on to document the anti-Semitic, anti-Zionist, pro-Hamas stance taken by "the UK's largest teaching union" which has sought to "globalize the intifada." Hinderaker concludes that policy, if implemented, would make "it impossible for Jews to live safely anywhere.
COTTonLINE agrees teachers (and professors) unions are a malign influence and should not be lawful. Most teachers and professors are civil servants, are therefore sufficiently sheltered by those statutes, and consequently do not need union protection.