A legislator who has a personal interest in a transaction shall disqualify himself from participating in the transaction. Unless otherwise prohibited by the rules of his house, the disqualification requirement of this section shall not prevent any legislator from participating in discussions and debates, provided (i) he verbally discloses the fact of his personal interest in the transaction at the outset of the discussion or debate or as soon as practicable thereafter and (ii) he does not vote on the transaction in which he has a personal interest.