In parliamentary democracies referendums generate alternative, competing sources of legitimacy. This has been clearly demonstrated by the EU referendum result, with the public voting to Leave despite a clear parliamentary majority for continued membership. Nat le Roux discusses this paradox and suggests that it would not be unreasonable for some MPs to choose to vote against the invocation of Article 50.
In a parliamentary democracy, referendums are potentially destabilising because they generate alternative, competing, sources of democratic legitimacy. A majority of elected representatives may hold one view on a matter of major national importance. If a referendum demonstrates that a majority of the public hold the opposite view, which manifestation of democratic legitimacy should trump the other?
In Britain, parliamentary sovereignty is the governing norm of the constitution: it would seem to follow that a parliamentary majority can always overturn a referendum result. The reality, at least in the particular circumstances of the EU referendum, is less clear cut:
- The referendum result will be implemented, effectively irrevocably, if Britain invokes Article 50 of the Treaty on European Union. It may be that the Prime Minister can do this without consulting parliament. If that is so, it can be argued that we now have a new constitutional principle under which, at least in particular cases, popular sovereignty as expressed in a referendum trumps parliamentary sovereignty.
- On the other hand, if the invocation of Article 50 does require legislation, we should ask under what circumstances, and by what arguments, MPs can overturn the directly expressed views of the electorate without severely damaging the democratic legitimacy of parliament itself.