The Supreme Court will rule this morning on whether the government spent public money on a one-sided campaign for the Children's Referendum.
Engineer Mark McCrystal is appealing the High Court's rejection of his claim that the government used €1.1m euros from the public coffers to promote a 'Yes' vote this Saturday.
He objected to content on the campaign website in a booklet sent out to households and in advertising ahead of the referendum.
High Court President Nicholas Kearns found the material was neutral and balanced.