Code of Organization and Civil Procedure (Cap. 12), article 728

728. (1) Subject to the provisions of article 731 in actions instituted by sworn application, all pleas whether dilatory or touching the merits shall be raised in the sworn answer, as the case may be. Those pleas touching the merits shall be raised without prejudice to the dilatory pleas. (2) No other pleas can be set up at a later stage; provided that the court may on an application by the defendant or respondent allow the setting up of additional pleas, if it is satisfied th at there were valid reasons for not includ ing them in the note of pleas or in the answer. Power of court to hear merits of case in order to dispose of preliminary plea.