Generally once a judge has made a decision the court draws up and seals the order. Subject to any appeal and enforcement that is an end of the matter. It is not quite as simple as that says the Supreme Court in Re L and B (Children) [2013] UKSC 8:
"[44] ... if a judge were entitled to change his mind a party would presumably be entitled to invite him to do so. No doubt most judges would do their best to have no truck with the invitation. But could the party be prevented from pressing for the exercise of the jurisdiction on the basis that in his first judgment the judge had failed to weigh certain evidence sufficiently or at all? In effect the judge would be invited to hear an appeal against himself. There is a distinction between an appeal and a variation for cause....
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