Dear all

If a tenant purports to sub-let, in breach of the terms of their
lease, they are clearly liable in damages to the head landlord for
breach of contract. I wonder however, if anyone could point me to any
authority on the liability (if any) of the sub-tenant to the head
landlord, arising out of the sub-tenant's occupation of the property
which the landlord had leased to the tenant?

I am thinking in particular of causes of action like inducement to
breach of contract, interference with economic relations or perhaps
conspiracy (between the tenant and sub-tenant), depending on the facts
and in particular what the sub-tenant knew of the lease before
sub-letting. My understanding is that a claim in trespass would not
lie, since the landlord does not have the right to possession of the
land which it has leased to the tenant.

If a sub-tenant went into occupation without knowledge of the lease
but declined to vacate when made aware that their occupation
constituted a continuing breach of contract by the tenant, would the
landlord thereafter have a cause of action against the sub-tenant for
continuing the breach of contract with knowledge?

I am not, I hope, using the list as a substitute for my own research
and will be happy to share any authority I do dig up with anyone who
may be interested in due course.

Kind regards

Ger