‘I myself would consider that there [are] advantages in making it clear that ultimately there are even limits on the supremacy of Parliament which it is the courts’ inalienable responsibility to identify and uphold.’
Lord Woolf, ‘Droit public – English style’  PL 57
State X has a BIT in force with State A that provides for investor-State arbitration of disputes concerning only the amount of compensation due in the event of an expropriation. It also provides for most-favoured-nation ("MFN") treatment "in all matters governed by this treaty". State X has a BIT in force with State N that provides for investor-State arbitration of any dispute arising under the treaty (and also provides for full compensation for direct or indirect expropriation). May an investor from State A initiate investor-State arbitration against State X for a claim of indirect expropriation relying on the MFN clause?
The Right is... Conditional
Citizens of the European Union now enjoy the right of free movement and residence within the territory of Member States. However, the exercise of this right is conditional upon claimants meeting certain requirements for the acquisition and retention of residence rights. Those conditions sometimes appear to be a significant barrier for the development of the free movement of persons.
Among the numerous cases brought to ICSID in recent years, Maffezini v Kingdom of Spain stands out as raising issues concerning the Most-Favoured-Nation clause.
A turning point in history
Roughly 100 years ago Frenchman Louis Blériot became the first man to fly across the Channel in a heavier-than-air aircraft, on 25 July 1909. The mustachioed aviation enthusiast and inventor was one of three pilots to respond to a public challenge to become the first man to achieve the feat. The British newspaper magnate Lord Northcliffe had offered a prize of £1,000 (equivalent to £115,000 in 2018) to the first person to make the flight in either direction.