election, all of them shall be referred for trial to the same judge, who may, in his discretion, try them separately or in one or more groups. (4) Any candidate not already a respondent shall, upon application made by him to the High Court within 14 days from the date of commencement of the trial and subject to any order as to security for costs, which may be made by the High Court, being entitled to be joined as a respondent. Explanation.— For the purposes of this sub-section and of section 97, the trial of a petition shall be deemed to commence on the date fixed for the respondent to appear before the High Court and answer the claim or claims made in the petition. (5) The High Court may, upon such terms as to costs and otherwise, as it may deem fit, allow the particular particulars of any corrupt practice, alleged in the petition to be amended or amplified in such manner, as may in its opinion, be necessary for ensuring affair and effective trial of the petition, but shall not allow