It sends a shiver down the spine. France's lower house has passed a law banning the wearing of the full Islamic veil – covering the face – in public places. The hope has to be that this extraordinary decision never actually reaches the statute book given that France's highest constitutional body, the council of state, warned some months ago that a ban would infringe constitutional rights and the measure could be challenged in the European court of human rights. Belgium and Spain are also considering bans on the veil. What makes the decision in France so disturbing is that it fits into a pattern emerging across Europe of a particular paranoia, as an open letter published today on Comment is Free and signed by more than 30 academics and commentators warns.

The veil debate is making it entirely legitimate to pillory, mock and ridicule a tiny number of women on the basis of what they wear. French politicians described the full veil as a "walking coffin"; on comment threads online there is contempt and sneers for the full veil and those who wear it – "hiding under a blanket", "going round with a paper bag over your head". In France it is estimated there are only 2,000 women who cover their faces with the burqa or the niqab out of a Muslim population of five million. The response is out of all proportion.

Let's be clear: the niqab and burqa are extreme interpretations of the Islamic requirement for modest dress; few Islamic scholars advocate their use, and many – including Tariq Ramadan – have urged women not to use them. They are as alien to many Muslim cultures as they are to the west. And yes, there are instances of patriarchy where some women might be encouraged or even forced to wear a full veil by their husbands or fathers. But generalisations don't fit. Increasingly, young women are choosing to wear the full veil, seeing it as a powerful statement of identity.

Invoking the full weight of the state to police dress codes in public is an extraordinary extension of state powers over an aspect of citizen behaviour which is largely regarded as your own business. Provided you are wearing some clothing, western public space is a free-for-all, and across every capital in Europe that is strikingly self-evident.

Women wearing the skimpiest of mini-skirts sit down on buses next to other women in saris, business suits, salwar kameez. None of these cultural codes expressed in dress are regarded as the business of the state. Nor should they be. Public space in the west has been crucial to the generation of a civic culture of tolerance; this is where strangers rub shoulders, sometimes sharing nothing but geographical space for a period of time – five minutes in a bus queue. We have negotiated and tolerated differences – of class, culture, nationality and race – in our streets and squares, and the lapses from that crucial ambition have been shaming.

It is not difficult to see the racism which permeates this debate. It is about assertion of identity – under the soubriquet of protecting "our way of life" – and crucial to that is forcing a choice: do you subscribe or don't you? Sign up or get out. But such choices are notoriously slippery. Who gets to decide what our way of life is exactly?

The Tory backbench MP Philip Hollobone, who is proposing a private members' bill to ban the veil in the UK, said that part of the British way of life is "walking down the street, smiling at people and saying hello". How many UK streets ever matched up to his rosy nostalgia? It exposes the absurdity of politicians trying to legislate some idealised past back into existence.

The irony is that these bans reveal a fixation on identity and the face at a time when more people spend more time than ever interacting online with complete anonymity. We can remodel our faces through cosmetic surgery or adopt an entirely new image for our virtual life. Most people navigating urban public spaces studiously avoid each other's eye. Yet many of those advocating bans have insisted that exposure of the face is crucial to interaction.

It is not too hard to understand that some women – a small minority – might find the pervasive sexualisation of western culture deeply offensive, and might want to signal by their clothing their disengagement and alienation. They don't want their face surveyed by that western glance which sizes up and categorises – to be dismissed or desired. Yet this is a choice which largely male politicians in France have chosen to remove (less than 20% of the French lower house are women).

French politicians insisted on Tuesday that women need to be liberated from the full veil. Forcing people to be free has a long and undistinguished history – well described by many, including George Orwell – yet too many times an age is blinded by its own prejudices and forgets that liberation can never be imposed.