As the Mental Health Bill 2025 came in to being after the Mental Health Act review, there was discussion about whether the MHA principles found in the Code of Practice to the Act should be moved in to the Act itself. The Mental Capacity Act‘s guiding principles are statutory, in s1(1) MCA and that was one of the arguments in the review: to make the MHA’s principles a part of the law itself.
Those wonderings made me realise, I had never written a blog post on the least restrictive principle in the MHA – it’s mentioned in passing in countless blogs, but I’d never sat down and rolled it out in the context of police decision-making despite there being situations where this is relevant and where its cited by the police to justify action or inaction in a particular circumstance.
So let’s see where this one goes.
CHAPTER ONE
The Codes of Practice, for both England and Wales, begin with a chapter which sets out the principles of the whole Act, so the least restrictive practice (ENG) or least restrictive option (WAL) is up front. The two codes do say very similar things, so I’ll paraphrase them both in one go –
It will not be necessary to undertake a restrictive intervention without that being necessary to ensure the safety of a patient or others; any restriction imposed should be the minimum necessary to achieve the objective.
An example may be useful –
The police attend to a man reported to be on the wrong side of a bridge, over main railway line. The road over the line is closed, negotiators are summoned and after a few hours, the man is persuaded to climb back over. During the incident, it has been established the man has been expressing suicidal ideas for days and his family have been calling on community mental health services to “section” him but no-one from his family can be raised during the period on the bridge.
The police now have a few decisions to make, but chief amongst them and the first one to be encountered is the issue of whether he should be detained under s136 Mental Health Act or helped on a voluntary basis, if he is willing.
This is, in some respects, a complicated decision, taking in to account a number of factors such as his right to life and his right to liberty. They have a duty, to at least some degree, to make sure he’s sent down a route which recognises his vulnerability, their duty of care towards him after having had contact where his human rights are engaged and the need to mitigate foreseeable risks. But they also must recognise his right to make as many of his own decisions as possible, free from state interference and to go about his business without his liberty being unnecessarily restricted by the state.
So – are you detaining him; or are you not?
ALTERNATIVES TO DETENTION
Key to all of this, might be what other options actually exist in the real world, at that time, in that place and context? Over a decade ago when “street triage” schemes were emerging, we kept hearing senior people involved with them, celebrating that use of s136 MHA had reduced after the scheme came in and I will admit, I was thinking “No sh*t, Sherlock!” Why were we surprised to see reduction in the use of a legal power designed to take people to services, if all of a sudden services could come to people, instead?!
But we also know other alternatives are considered, including police assisting people to access services voluntarily (crisis centres, Emergency Departments, 111 (option 2) services, etc.) and informally safeguarding people by dropping them to relatives or friends and / or referring people to other services who might follow up with them the next day or so.
The challenge is how to weigh all of this stuff and determine what is the least restrictive approach in a given situation? Well first things first, the actual least restrictive thing is always going to be let people go on their way, unincumbered by the machinations of the state, but we always need to ask whether that mitigates any immediate risk to life, assuming the situation is sufficiently similar to our hypothesis, above?
IMMEDIATE RISK TO LIFE
We need to quickly cover this again: what is an “immediate risk to life”, in law? – for a fuller explanation, click the link just offered in the previous paragraph for an earlier post of mine but for now, be reassured the definition is “a real and immediate risk which is present and continuing, which is not fanciful or trivial.” And if it assists to use the words “probable” and “possible” in terms of how we would verbalise the risk of someone’s death, an immediate risk to life obligation can be engaged where death is not thought “probable”, but is still “possible”.
In the particular case where the Supreme Court definition emerged, there had been formal suicide risk assessment of a psychiatric patient who was considered to be “5-20% risk” of death, whether accidentally or intentionally and that was enough to engage the so-called operational duty, under Article 2 for an immediate risk to life.
So where does this leave our officers above the railway line? – they have to consider whether any alternative action is an acceptable mitigation of the risk someone may die or suffer serious harm and because so much is at stake, there would have to be a reasonable likelihood it would work.
But it’s about more than the immediate detention and very short-term risk.
WHAT ARE WE ENSURING?
Detention under s136 Mental Health Act 1983 is not just about ensuring immediate safety. It’s also about ensuring a proper outcome to manage that risk over coming days or weeks. Other cases have shown that failures in the operational duty can include events around eighteen days before someone’s death.
Back to our hypothesis: we know community mental health services were thinking the patient may need to be “sectioned” and family were thinking that too. Well, we know you ignore family members at your peril and s136 MHA ensures an Approved Mental Health Professional (AMHP) and a doctor assess the person and make necessary arrangements for someone’s care.
Would any of the alternatives to detention ensure similar outcomes in terms of immediate risk and ongoing care? – perhaps they could, but we would need to think about the willingness, ability and likelihood of the patient engaging with that. Were it thought reasonably foreseeable a patient would simply not engage with that, perhaps s136 starts to become more likely as the relevant outcome despite it not being the least restrictive choice amongst all the options.
The punchline of all this:
- The least restrictive principle is not about doing the very least restrictive thing – it’s really not.
- It’s about doing the least restrictive thing consistent with safety, whether that be the person themselves or wider public safety, as far as it is ever possible to do such things.
Declining to use section 136 where the alternatives on offer simply cannot bring about a short-term mitigation of risk and / or the required professional assessment to mitigate risks in the medium term, cannot be defended by simply saying “it’s the least restrictive principle”.
That’s just not what it means.
Awarded the President’s Medal, by
the Royal College of Psychiatrists.
Winner of the Mind Digital Media Award
All opinions expressed are my own – they do not represent the views of any organisation.
(c) Michael Brown, 2026
I am not a police officer.
I try to keep this blog up to date, but inevitably over time, amendments to the law as well as court rulings and other findings from inquests and complaints processes mean it is difficult to ensure all the articles and pages remain current. Please ensure you check all legal issues in particular and take appropriate professional advice where necessary.
Government legislation website – www.legislation.gov.uk
Mental Health Cop 