If a section 3 patient is placed on s48/49 does the s3 expire or should it be discharged?
I don’t see why a patient can’t be subject to both. In R (Stewart) v Managers of the NW London MH NHS Trust [1997] EWCA Civ 2201 - Mental Health Law Online, the Court of Appeal noted that " Part II (civil) and Part III (criminal) powers can co-exist and operate independently of each other".
I suppose the Section 3 should be discharged, but note that if the patient’s court case is discontinued, they are given a community disposal/time served or found not guilty, the Section 48/49 will expire and if the hospital wish to keep them longer, they will have to apply for another Section 3 regardless.
It doesn’t expire- you would have to discharge it or not renew it. We have come across this the other way around more usually, ie S48/49 pt and we anticipate a collapsing trial/ out on time served where we may place on concurrent s3, so we can return to hospital and continue treatment, although some areas are adverse to doing this and it has become more contentious in recent years. In your case the treating team may want to keep it in place as ‘cover’.
The s3 automatically ends when the patient is admitted to hospital under s48/49 - see s40(5) MHA read with ss47(3) and 48(3). There is no need to discharge it.
It doesn’t work the other way round, - a new s3 wouldn’t end the s48/49. So (as Zac and Ian say) the two can in principle operate side by side - but only if the s3 comes second.