Theresa May is no idol for human rights activists: home secretaries rarely are. She and Chris Grayling have caused much harrumphing by expressing their hostility to – either or both, it is not clear which – the European Convention on Human Rights and the Human Rights Act. A recent article by the home secretary in the Mail on Sunday set out her views in their most extended form so far.

The headline, no doubt dictated by a special adviser, said, somewhat loquaciously: ‘It’s my job to deport foreigners who commit serious crime – and I’ll fight any judge who stands in my way, says home secretary’. That provides a pretty good summary but the content deserves a bit of unpicking.

Underneath the bluster, May makes the following serious, and constitutional, points. First, she accepts judicial review of ministers by ‘independent judges who are appointed, not elected, and who are not accountable to the electorate for their decisions’. Indeed, she is ‘a great admirer of most of the judges in Britain’. Well, that is a step forward from the position of some of her Labour predecessors, notably the populist David Blunkett.

Second, human rights are ‘an essential part of any decent legal system’. She is explicitly not in ‘a dispute about respect for human rights’. Wow. Third, article 8 of the European convention, which protects the right to family life, ‘is not an absolute right, like the right not to be tortured. It is a qualified right and it can be restricted… for example to protect public safety or for the prevention of crime’. In the words of The Wire’s linguistically challenged but strangely engaging villains: ‘True, dat.’

Beyond this point, May’s argument becomes more jumbled – partly right, partly confused. ‘Some of our judges’ are wrongly construing [the right to family life] as an absolute right. As a consequence, they are routinely blocking the deportation of foreign criminals who have family in this country ‘regardless of the gravity of the offence’. Such judges are disregarding the expressed will of parliament because the House of Commons unanimously approved the latest version of the Immigration Rules, which attempted to attach less weight to the right to family life in deportation cases. Hence, she has no option but to introduce primary legislation.

May makes clear references to the case of Izuazu [2013] UKUT 45 (IAC), to which it is worth referring before taking on her substantive arguments. At this point we should remember that the history of the law is written by judges and academics, but many a solicitor knows it is more complicated than they usually admit. To put it at the lowest: your client does not improve their chances of success if you forget the hearing date, mess up the bundles or bungle the pagination.

This case was heard by three senior judges including Lord Bannatyne and Sir Nicholas Blake, president of the Upper Tribunal. This was not a good bench before which to appear without all the papers, as the senior Home Office presenting officer did. Nor one which was going to contain its ‘dismay’ when asked to adjourn in consequence. It does not help your case to provoke judges into expressing their ‘dissatisfaction at the appellant’s lack of preparedness’ and ‘not for the first time… a failure by the [UK Border Agency] of its duty of co-operation with the tribunal’. Who is to say whether the judgment would have been different if the UKBA had been more competent? May can splutter all she likes, but her civil servants manifestly did not take the matter as seriously as she now does.

These were not judges that were going to be crass. Of course, they accepted the balance in article 8 and explicitly followed Lord Bingham’s exegesis on how to apply it. They considered the Immigration Rules and noted established authority that they were ‘not subordinate legislation but detailed statements by a minister of the Crown’ (Odelola v SSHD [2009] UKHL 25). This is the heart of May’s mistake. She and her advisers should have read their Dicey. He was always very clear that parliament is supreme, just as May argues, but that parliament consists of both houses and the Crown, as she neglects to note.

May promises us more of her views on the content of the next Tory manifesto. Meanwhile, she holds the remedy to her immediate problem in her own hands. She needs parliamentary legislation even if she is afraid that the Lords will baulk at it. Then, the Human Rights Act is clear. Every domestic judge will follow her statute even if they declare it incompatible with the European Convention on Human Rights. She can then argue her point in Strasbourg: although it would be a good idea for her advocates to be better prepared.

Roger Smith is visiting professor at London South Bank University and former director of human rights group Justice