A plaintiff who has secured a prejudgment remedy prior to May 30, 1973, may make a motion to the court in which such action is pending for a hearing as set forth in section 52-278d with notice thereof to the defendant or his attorney. If the court, upon consideration of the facts before it, finds that the plaintiff has shown probable cause to sustain the validity of his claim, such prejudgment remedy secured shall be effective from the date of such hearing and an order to that effect shall be issued by the court. Any such prejudgment remedy which is not perfected on or before October 1, 1977, shall be void and of no effect.