The father of maths teacher Jeremy Forrest will today make a public appeal for his son to return home with his runaway teenage pupil, Megan Stammers.
Jim Forrest will speak to the media at Sussex Police HQ at 3.15pm as the search for the pair continues a week after they eloped across the Channel, Sussex Police said.
The last confirmed sighting of Megan, 15, and 30-year-old Forrest - who taught maths at Bishop Bell C of E School in Eastbourne, East Sussex - 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.
At the news conference, Chief Inspector Jason Tingley will also speak about the inquiry into the missing pair and "clarify the status" of the European inquiry.
It comes amid confusion over how intensely the search is being carried out on the Continent, with reports claiming that French police are not actively looking and have not carried out standard credit card or mobile phone checks.
BBC News reported that Interpol was unable to confirm that it is working on the case.
Neither Megan nor Forrest has a profile on the crime agency's website, http://www.interpol.int, under its "yellow notices" section which "help locate missing persons, often minors, or to help identify persons who are unable to identify themselves".
Forrest is also not listed under the website's "red notices" - profiles used "to seek the location and arrest of wanted persons with a view to extradition or similar lawful action".
Questions over the scale of the search abroad came as Megan's family thanked people for their support in spreading appeals online.
The schoolgirl's stepfather, Martin Stammers, 43, tweeted today: "Please continue your efforts, if I could thank you all individually I would, your help is invaluable I implore you to RT £findmeganstammers."
One of Megan's friends, Casie Barnes, 15, who lives a few doors away from her family in Eastbourne, said she would never have imagined she would enter a relationship with Forrest.
She told ITV's Daybreak: "I'm really concerned. I really want her back. Her family, friends, everyone just wants her back safe and soon."
Asked about the relationship, she added: "I'd never put them both together as a couple. She was a shy girl."
Casie's mother, Kersti Barnes, said Megan's family "want to be left alone" but are grateful for the support they have received in trying to find the teenager.
She said: "I can't begin to imagine how they are feeling because obviously she's in a different country."
Casie said Megan may be feeling frightened.
She went on: "She's scared, maybe she wants to come home, maybe she's embarrassed as it's all over the news, but whether she wants to come home, I don't know.
"I would be scared if I were in her shoes."