12. Joinder of parties

A tribunal or the Registrar may allow the joinder of parties and order that 2 or more claims involving 2 or more persons be heard together, if —

it appears to the tribunal or Registrar that —

doing so is convenient;

a common question of law or fact arises in all the claims; or

all rights to relief claimed (whether they are joint, several or alternative) are in respect of or arise out of the same transaction or series of transactions; and

such a joinder does not prejudice any party to any of those claims.