In today's Queen's Speech the Government announced plans to limit the use of Article 8 of the European Convention on Human Rights. The changes are likely to be popular, thanks to longstanding campaigns by some newspapers to restrict the rights of foreigners who have committed crimes here.

But there are reasons why we should be very wary about this proposal, as it could greatly alter the balance of power between judges and the Executive.

The proposals themselves are a bit vague. The new Immigration Bill will:

give the full force of legislation to the policy we have already adopted in the Immigration Rules. The courts would therefore be required to properly reflect the balance given to the public interest when ruling on immigration cases.

Helpfully, the Daily Mail has some more detail:

The legislation will add legal weight to guidance for judges introduced last July by Theresa May that foreign criminals should be able to use Article 8 of the Human Rights Act in exceptional circumstances only.

What should we make of this? Let's start with the basics.

Article 8 of the European Convention on Human Rights is sometimes said to give people an unqualified right to family and private life. That is simply wrong. The full text begins by saying that "everyone has the right to respect for his private and family life...". But it goes on. The right can be interfered with by public authorities if that interference is:

in accordance with the law and is necessary in a democratic society in the interests of national security, public safety or the economic well-being of the country, for the prevention of disorder or crime, for the protection of health or morals, or for the protection of the rights and freedoms of others

So the first thing to understand is that Article 8 is already heavily 'qualified'. Judges know this. They can, and regularly do, decide that national security and public safety trump a person's right to family and private life. Indeed, primary legislation already tells judges that deportation for serious crimes is "conducive to the public good".

Fact sensitive

How do judges decide? Any decision about human rights involves a fact-sensitive balancing exercise. Tribunal judges will usually hear oral evidence and decide, for example, how close the person threatened with deportation is to their three young British children, and how badly the children will be affected. They will also consider evidence of the seriousness of that person's crimes, their likelihood of reoffending and the threat to public safety of them staying in the country. They will then reach a decision - such as this one.

The crucial thing to understand is that Parliament - through the Human Rights Act - has given judges the job of interpreting whether public authorities have breached individuals' human rights.

The reason for this is simple. Public authorities, such as the Home Office, have a legal duty to act in a way which does not breach human rights. If they fail in that duty, an individual can take them to court to enforce their rights. Logically, public authorities shouldn't be the judges in their own cases, which is why judges are brought in to referee. That is central to our balance of power system: Parliament decides the law, judges determine whether public authorities are acting within the law.

Perverse decisions

The Home Office is invariably the respondent in decisions about deportation. It is on one side of the case, and sometimes loses but also regularly wins. When the Home Office loses, like any party to litigation, it has the right to apply to appeal the judgment.

It is also open to a Home Secretary to argue that judges' decisions are so perverse that the basic balancing exercise needs to be taken out of their hands by changing the law. That is what is about to happen. It seems that the Home Office wants to upgrade recent immigration rules changes to primary legislation, which would prevent courts from ignoring them in favour of the ordinary Article 8 balancing exercise. Most notably, in some foreign deportation cases "it will only be in exceptional circumstances that the public interest in deportation will be outweighed by other factors".

But as you might have guessed, this is a big step - a Rubicon is being crossed. The Home Secretary's view on Article 8, and where the balance lies, will be forced on judges. It is a bit like an under-pressure football manager convincing the Football Association to make the space between his team's goal posts narrower.

So, before taking such a big step, we need to ask whether there is sufficient justification.

The first place to look is the newspaper campaigns I mentioned earlier. I have some sympathy with those campaigns - for example this widely criticised Tribunal decision does seem to somewhat stretch the boundaries of Article 8. More generally, whilst the Home Office should not be able to deport who it likes with impunity, people who commit serious crimes and who have no leave to be here should generally be deported.

But there are a few problems with the campaigns too. First, the reported cases are often misrepresented, and when considered further seem a lot more marginal - like this one.

Second, even if there are some perverse decisions, it is by no means clear that those decisions are a representative sample. The figures are regularly fiddled, and for all of its protesting, the Home Office itself has not published a detailed analysis either.

Third, the newspapers are regularly fed tribunal judgments which are supposedly wrong, but we rarely hear about the Home Office appealing those judgments. If they are so perverse as to require restricting basic rights, surely the Home Office should appeal them before attempting to change the law? The reality is that many failed deportations are due to incompetence and unacceptable delays in dealing with cases - such as the case of Aso Mohammed - not flaws in judicial reasoning.

Crossing the Rubicon

It is therefore doubtful that there is enough justification for these changes. But even assuming there is, and we cross this Rubicon, where does it stop? It is easy to imagine other public authorities arguing that judges have been making perverse decisions in their human rights cases, so we need a "rebalancing" there too, such as in relation to sex offenders or prisoners.

You might think that is fair enough, but restricting rights for unpopular groups invariably has unintended consequences. Which is exactly the reason Parliament has given the job of balancing rights to impartial judges rather than partial politicians. And whatever the Home Office proposes, this bill is likely to lead to open season on the Human Rights Act, with much more extreme proposals, such as preventing criminals altogether from using human rights protections, in the pipeline.

There are very good reasons for letting judges, not politicians, decide whether public authorities have breached individual rights. We should therefore be very careful indeed before letting the Home Office load the dice in human rights cases.

Adam Wagner is a barrister at 1 Crown Office Row specialising in human rights and medical law. He is the founding editor of the UK Human Rights Blog and tweets as @adamwagner1.