Jones v London Borough of Merton  EWCA Civ 660 addresses whether a tolerated trespasser’s liability to pay mesne profits ends when they leave the property or when they notify the former landlord that they have left.
Ordinary trespassers are only liable for mesne profits for the period of actual occupation of a property. Merton submitted that tolerated trespassers were in a different position. Public policy required that housing authorities be notified as soon as possible that occupation was at an end to enable re-letting. There was a direct analogy with the requirement that a secure tenant end the tenancy by notice to quit under s.5 Protection from Eviction Act 1977 as the tolerated trespasser had a distinctive status.
The Court said this was not so. The only valuable, distinctive right of the tolerated trespasser, the right to apply for revival, ends when execution is no longer required to give effect to the possession order, which is when the trespasser has left the property. Liability for mesne profits only extends to the period of actual occupation and there is no requirement for formal notification of giving up occupation to the landlord.
On a side note, possession (as in occupation) requires both factual possession and intention to possess. One cannot be said to have given it up until there is no intention to possess. JA Pye (Oxford) Ltd v. Graham  UKHL 30 applied. There is some dissension between the judgments as to when, on the facts of the case, this was manifest in this case.