I don't think the burqa/veil issue should be considered a religious one. What one should wear is basically not a spiritual question. To decide whether females should be allowed to dress thus, one must look at the consequences.
People too often fail to distinguish the consequences to a particular female in wearing skimpy clothing from the consequences to females in general in wearing skimpy clothing. Probably when a female wears skimpy clothing, she does put herself in greater risk of being sexually assaulted, but she doesn't put females in general at greater risk; in fact she makes other girls safer an amount that cancels the amount she puts herself at greater risk. If a girl were to wear a bikini top and skimpy shorts to school, that would probably put her at greater risk of being sexually assaulted, but if most girls standardly wore bikini tops and skimpy shorts to school, they would be in no more danger than they are at present. Dangerwise, it's how girls dress relative to other girls that matters. When a girl dresses with excess modesty, she puts other girls at greater risk of being raped.
The worst consequences to females dressing with excess modesty are on the males. How are young males supposed to figure out their natural feelings toward females if they aren't very much allowed to see females? Also, how can males go about choosing a mate very well if they are not allowed to look at them before mating? Higher moral traits tend to arise from sexual selection, which can only work at best half way if males can't look at females before dating or mating with them. If females aren't inferior in such a society, they will quickly evolve to become inferior, because males can't very well use sexual selection to select for desirable female traits if they can't see females before promising to love them. True, perhaps males can judge females more by conversation, but considering judging by appearances as evil should be seen for what it is, namely as mostly something cooked up by snobby rich people who have greater social connections and wish to keep it that way by making it impossible for people outside their circle to easily form connections with their own circle. Fashion and personal visual self-expression in a society are keys to reducing class snobbery and cliquishness, and should never be trivialized. Of course, there is the argument that females should be free to wear whatever they want if it doesn't hurt others, but like I said, females do hurt others by dressing too modestly--they put other females at danger.
Most western schools presumably already have dress codes against excessively immodest clothing, and so dress codes against excessively modest clothing would be a reasonable symmetric counterpart. Muslims can't have it both ways and argue it's not a religious issue when they don't want others to mock their religion (such mocking of their religion would be well deserved if in fact that be a part of their religion) but then argue it's a religious issue when they want to send their daughters to school dressed obnoxiously.
Not that there isn't a point to dress codes the other way. People going to school naked might be a health issue if nothing else. And if people went around naked, that would make rape a non-neglible amount easier, there being no clothes to take off beforehand. And females tend to like to de-emphasize the "hole" nature of their sexuality, that being the sort of thing that might appeal to "woot! hole!" males, yeah, who more tend to be pro-sodomy (and thus disgusting) than males more enthusiastic about other aspects of female sexuality. Similarly, I don't have a problem with schools having rules that shorts must cover completely one's hindquarters, though I do remember thinking maybe it a little much some school taking rulers to girls' shorts trying to decide if they were sufficiently below the hip line. Mostly, true modesty (the good kind) is about expressing clean sexuality as opposed to little sexuality. A girl dressing like she finds sex very interesting or wants great sex is innocuous and is different from a girl dressing like she loves sex with scads of males or like she loves what is disgusting, and females in skimpy clothes usually probably is more about the first. Nay, females tend to most importantly love with sex, and so to deride sexuality in females or the expression of such is to deride females for their most unselfish traits or their expressions of such--it is a wicked thing to do.