The father of missing maths teacher Jeremy Forrest made an emotional appeal to him and his teenage pupil Megan Stammers to "get in contact".
Jim Forrest fought back the tears as he appeared alongside his distraught wife to make the appeal a week after the pair boarded a ferry to France.
The pair, from Eastbourne, have not been seen or heard from since despite desperate pleas by Megan's parents.
Sussex Police confirmed that a European Arrest Warrant had been issued for Forrest for child abduction.
The last confirmed sighting of Megan, 15, and 30-year-old Forrest - who taught maths at Bishop Bell C of E School in Eastbourne - was from CCTV cameras on board a Dover-to-Calais ferry at 9.30pm last Thursday.
The release of two images of the pair, arm-in-arm and holding hands, was intended to trigger a response from the public about their whereabouts.
Chief Inspector Jason Tingley said there have been "rumoured sightings" in Europe of the missing pair.