Don't know and don't really care. My interest is that a British MP can apparently 'officially' lobby a foreign government - the question is under who's authority?
Doesn't say anything about dual nationality one way or the other.
'People wishing to stand as an MP must be over 18 years of age, be a British citizen or citizen of a Commonwealth country or the Republic of Ireland.'
Who can stand as an MP?
ETA: Apparently Australia is the only Commonwealth country to ban dual nationals from becoming MPs although given recent events with Chinese dual nationals, I wouldn't be surprised if NZ isn't thinking the same way.