"Does the leader of the opposition have to recite an oath of office (as leader of opposition) over and above his/her oath as MP? "

Thanks for your question, Laurie. 

The Leader of the Opposition does not recite an oath or affirmation that is specific to their role as leader. 

The Australian Constitution requires that members of the House of Representatives and senators affirm their allegiance to the Crown. All are required to both ‘make and subscribe’ (sign) an oath or affirmation. The same oath and affirmation have been used since federation and can only be changed by a referendum. Members and senators can decide whether they would like to swear the oath or the affirmation.

OATH

I, ……………, do swear that I will be faithful and bear true allegiance to Her Majesty Queen Elizabeth the Second, Her heirs and successors according to law. SO HELP ME GOD!

AFFIRMATION

I, ………………., do solemnly and sincerely affirm and declare that I will be faithful and bear true allegiance to Her Majesty Queen Elizabeth the Second, Her heirs and successors according to law.

diagram to help explain Does the leader of the opposition have to recite an oath of office (as leader of opposition) over and above his/her oath as MP?