The father of maths teacher Jeremy Forrest appealed directly to him and his teenage pupil Megan Stammers today, saying: "Please, please get in contact."
Jim Forrest fought back tears as he appeared at a police press conference to urge the pair to come home.
He said: "Hi Megan, hi Jeremy, I hope this message reaches you and you are both okay. There are a lot of people back home that are desperate to hear from you. All I am asking is for one of you to make a call, send an email, so we know you are both safe. We are all here for you both. Please, please get in contact."
Mr Forrest, from Petts Wood, south east London, appeared alongside his tearful wife Julie 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 have confirmed a European Arrest Warrant had been issued for Forrest for child abduction.
Mr Forrest senior thanked the force for "all they are doing in helping to bring Megan and Jeremy back home safely".
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. But there have been no further sightings, police have said.
Speaking at the same press conference Chief Inspector Jason Tingley said: "This has probably not gone the way that Megan or Jeremy expected. Jeremy will be aware that he has questions to answer, and making contact with us is the best way he can do this. As part of the process of working with the French authorities, we have secured an international letter of request and a European Arrest Warrant.
"These orders, which have been obtained with the help of the Crown Prosecution Service, enable us to work with the European authorities, and are in relation to an offence of child abduction. This means taking Megan without the consent of her parents. The full details of this warrant have been circulated to every EU country. When the pair are found in an EU country, Jeremy can be arrested and Megan will be taken into protection."