This was the question posed by Philip Rainey QC in his case update at the 15th ALEP Conference at the Royal Institution on 21st October 2014.
The case of Jewelcraft v Pressland (see http://www.leaseholdreformnews.com/jewelcraft-v-pressland/) does somewhat leave that question open. The facts of this case were very similar to Henley v Cohen (shop with flat above, no internal access). The landlord won at first instance and the tenants have now appealed to the Court of Appeal. More on this in the new year.