Requirement to issue reasoned decision in the last instance
Sri Lanka
Parliamentary Elections Act,No.1 of 1981
104. (1) The Supreme Court may,upon any appeal preferred under section 102 affirm, vary or reverse thedetermination or decision of the Election Judge to which the appeal relates.
(2) Where the Supreme Courtre:;;erves on appeal the determination of the Election Judge under section 100,that Court shall decide whether the Member whose return or lection wascomplained of in the election petition, was duly returned or elected, orwhether the election was void, and a certificate of such decision shall beissued by that Court.
(3) The Supreme Court may, inthe case of any appeal under :;;ection 102, order that the election petition towhich the appeal relates shall be tried anew in its entirety or in regard toany matter specified by that Court and give such directions in relation theretoas that OJurt may think fit.
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Source:
http://www.ifes.org/~/media/Files/Publications/Election%20Law/1981/IFES_18/EL00120.pdf