Save as otherwise provided in this Act, nothing herein shall apply to any election which has been called before the commencement of this Act or to any election petition arising out of such election, whether such petition is pending at such commencement or is presented afterwards, and all such elections shall be held and petitions tried, and all matters in connection with such elections or petitions (including the constitution of Election Tribunals) shall be regulated, in accordance with the provisions of the law in force immediately before such commencement.