The LP’s legal advice on a challenger induced leadership contest is allegedly posted here, on scribd, which is a subscription service. Bottom line, where there is no vacancy, the 20% threshold applies only to the challenger(s). I particularly like the idea that rules can’t be rubbish and because what they are trying, i.e. to apply a higher threshold of parliamentary support to a re-election is not in the rules and is rubbish, it can’t be done. It also notes that all the “is final” clauses, do not exclude the courts and cannot exclude access to the courts.