A grammar lesson in Parliament

No, not Trevor Mallard giving the subjunctive a bit of biff. This is from Parliament in London, where they discuss weighty matters such as Iraq and the Chilcott inquiry, Afghanistan, climate change, MPs’ expenses, the BAE enquiry and grammar.

Yes, grammar. From the 19 January edition of Hansard:

Denis MacShane (Rotherham) (Lab): [. . . ] There is no country keener on referendums than Switzerland.

Michael Fabricant (Lichfield) (Con): Referenda.

Mr MacShane: Referendums. It is a gerund.

Mr Fabricant: It is a gerundive.

Mr MacShane: It is a gerund. Keep your hair on. [. . . ]

Michael Fabricant: [later in the debate, after checking in the dictionary] The right hon. Member for Rotherham (Mr.MacShane) may have inadvertently misled the House earlier, and I am sure that he would wish to retract that. As the word “referendum” means “things to be referred”, according to the “Oxford English Dictionary”, it is indeed a gerundive and therefore the plural should be “referenda”. “Referendums” is acceptable in modern usage, though wrong.

Hon. Members: Withdraw!

The Independent comments:

The “keep your hair on” bit was a little cruel, because Mr Fabricant is famous for having a topping of blond hair which a lot of people think is not real. [. . .]
But, should you need to ask, [. . . ] a gerund has no plural form in Latin, therefore if “referendum” were a gerund, you could not say “referenda”, but since it is in fact a gerundive, “referenda” is correct. Correct, if a little pretentious. But I expect you already knew that.

Well, doh.