As the Conservatives try to get back into favour with women, new initiatives have been appearing on a daily basis aimed at recapturing the female vote. Last week Theresa May launched a Home Office consultation on proposals for a so-called “Clare's law”, which would give women the right to demand information from the police about the background and criminal records of their new boyfriends. The idea was floated earlier this year by Hazel Blears (remember her?), supported by the Victim's Commissioner and former “respect” tsar, Louise Casey, and has received the backing of the Sun newspaper. The law would be named after murder victim Clare Brown, who died in 2009 at the hands of her violent lover, a man she met through Facebook.

The proposal is that the police should use their new National Database to provide women with more information about their boyfriends, as a matter of course. At present, the police have discretion about the information they will supply in response to a request from a member of the public. Under “Clare's law”, they would be bound to give information to a woman asking for it (provided she can satisfy the police that she is in a relationship with the man in question), and might even be under a duty to “proactively” disclose such details.

The consultation document issued by the Home Office lays out the “cost-benefit analysis” of the proposed reforms. (In the inimitable words of our Home Secretary, I am not making this up.) Apparently the cost of domestic violence is £15.7 billion pa. If the “right to ask” option is adopted, the cost in extra police time will be up to £90,000 but the predicted “saving” will be between £0million (!) and £80million, resulting from a nil – 0.5% reduction in domestic violence. If the “right to know” option is adopted, this will apparently cost twice as much in police time but is guestimated to reduce violence by up to 1%, thereby conjuring up a “saving” of £160m a year.

What wonderful things you can prove with figures! Especially if you take a big enough one to start with. The Home Office confidently asserts that the “right to know” exercise will “break even” if it secures a 0.0003% (sic) reduction in violence. So it seems pretty clear that, regardless of the outcome of the consultation, Clare's law will be sold to an unwitting public as not only pro-women but also – roll of drums – cost-effective.

The costing exercise may look like a joke, but this is a serious matter. Clare's law is an ill conceived scheme and wrong at almost every level. First and foremost, it is unlikely to save lives; indeed it's hard to see how it would have saved Clare Wood. Clare met her boyfriend, George Appleton, on Facebook and died at his hands a year later, after the breakdown of their relationship. Her father admits that he took an instant dislike to Appleton; he believes that if Clare had been told by the police that he had been jailed in the past for harassment, she would have ended the relationship earlier. Perhaps she would, but that might only have precipitated Appleton's vengeful attack. By the time a woman is prepared to talk to a police officer about her boyfriend's character, it is likely that she is already in a violent or abusive relationship. Nowhere in the consultation does the Home Office suggest that everyone on Facebook should have access to the police database, so as to check out a new date before meeting offline. The privacy implications of such a proposal would, in any case, be deeply disturbing.

Privacy campaigners have already expressed concern about Clare's Law. If an offender has served his sentence and has been released, on the basis that he is no longer a threat to society, is it right that his record should be available to prospective girlfriends? If the database includes unproven allegations made by previous partners, or charges that were dropped, should the police “proactively” release this information? It is perfectly understandable that victims of violence should feel that privacy concerns are trivial when lives may be at stake. But their justifiable distress should not blind us to the implications of a such a programme of disclosure. We should also be mindful of situations where charges are made against former boyfriends in a spirit of vengeance, as well as the prospect of information being used to blackmail a partner or former partner.

Perhaps the Home Office is confident that enough safeguards can be put in place to prevent such misuse and to protect privacy. But the context of the consultation is not reassuring. The proposal is emotively linked to the horrible death of an attractive young woman, titling the review a “Consultation on Clare's law” and presenting Clare Wood's case as reason to act. Apart from its rather imaginative costings, it also contains a preposterously unrealistic objective, declaring that “The ambition of this government is to end violence against woman and girls.” Such grandiose language suggests that any worries about the right to a fresh start, the invasion of privacy, mistakes on the database, or simply the waste of police time, will all be batted aside.

Suppose, then, that these proposals are put into law. Does the Home Office envisage that all women (and indeed men, for the law is of course intended to apply equally) should consult the police database before going on a first date? If so, how will they satisfy the police that they are serious in their intentions, and not just making an idle or mischievous enquiry? Will they be pledged to secrecy as a condition of receiving the information, or will they be free to tell their friends – or maybe put it on their Facebook page? Supposing they decide to risk the date anyway – after all, lots of women stay in abusive relationships, hoping or believing their partner will change his (or her) ways. If they go to the police later, will the answer be: sorry, we did warn you off, don't come crying to us?

Underlying all this is the assumption that the Home Office will do our thinking for us, implying we can rely on a database to tell us if someone is safe to know. This approach led to the creation of nearly 50 different public service databases under the last government, including CRB checks and Integrated Children's Systems, encouraging the abandonment of common sense and personal experience in favour of box ticking.

By all means let the Home Office issue warnings that internet dating is dangerous, point out that moving in with a boyfriend is unwise until you've known him for more than a few months, and that most domestic violence occurs between partners who are cohabiting, not married. But don't make the mistake of thinking that a police check can ever be a substitute for personal judgement, common sense and caution.

One final thought. Did we get rid of a Labour government only to see laws being put forward by Blair's respect tsar in combination with the expenses-queen Hazel Blears, using spurious costings from the New Labour school of economic competence? Do you sometimes wonder why we bothered?