Kate McCann, the mother of missing Madeleine, has asked for permission to give evidence at the libel trial of the Portuguese detective Goncalo Amoral.
Gerry McCann has already made the same request. The judge is likely to decide on November 5th.
A BBC Crimewatch reconstruction of Madeleine McCann's disappearance will star a three-year-old actress as Maddie.
A small production team from the programme have spent a week filming abroad for the new appeal, which goes to air on Monday 14th October.
Crimewatch presenter Kirsty Young speaks to the McCanns in the new programme, while presenter Matthew Amroliwala has been to Praia da Luz in Portugal to explore the new focus of the police investigation.
The McCanns and the senior investigating police officer will also be live in the studio.
The Metropolitan Police have promised "targeted and new appeals" for information about Madeleine McCann's disappearance as detailed phone records are helping them build up a picture of who was in the area at the time.
Earlier this week, Scotland Yard revealed that:
- 41 people of interest have been identified
- These include 15 UK nationals
- 31 international letters of request have been sent, mostly European countries
- A large list of phone numbers belonging to people in the area has been drawn up
The senior investigating officer into Madeleine McCann's disappearance has said he hopes the forthcoming appeal will prompt new witnesses to come forward.
Metropolitan Police's Detective Chief Inspector Andy Redwood said: "We now believe we have the most complete picture to date of the events surrounding her disappearance.
"We are now making targeted and new appeals for help from the public.
"I truly believe there are people out there who hold the key to Madeleine's disappearance, and that so far they may be completely unaware of that fact."
Madeleine McCann's parents are "greatly encouraged" by new information about the disappearance of their daughter, they said in a statement ahead of a fresh appeal.
Next Monday, the BBC's Crimewatch will show a reconstruction of the "latest, most detailed understanding" of the events surrounding her disappearance, and a fresh appeal for information.
Madeleine's parents, Kate and Gerry McCann, said: "We are greatly encouraged by new information coming to light with pieces of the jigsaw now fitting together.
"We are really hopeful that the forthcoming appeal on Crimewatch will bring further new evidence which will take us a step closer to finding Madeleine and to bringing those responsible for her abduction to justice," they added.
Kate and Gerry McCann are to make a significant television appeal in light of "fresh, substantive" material unearthed as part of a British police investigation into their daughter's disappearance.
The McCanns will appear live in the studio during an episode of BBC Crimewatch on Monday October 14, which will also feature a reconstruction and pre-recorded interviews with the couple.
Scotland Yard is for the first time trawling through a vast log of mobile phone traffic identified in Praia da Luz, in Portugal, at the time of Madeleine's disappearance.
The effects of a book that made allegations about Madeleine McCann's disappearance were worse than when her parents were made arguidos, or formal suspects, Gerry McCann's sister told a court in Portugal.
In her evidence at the libel trial of former police chief Goncalo Amaral, who wrote the book, Trish Cameron said: "This was a different thing. It was much more conclusive and demonising them, dehumanising them, saying they did not care for their children, that they were responsible.
"It makes it out that they weren't truthful and they have been vilified and it's very hard to turn round opinion about them that has been so widely spread."
Mrs Cameron told the court that the Portuguese people had "turned against" the family, adding: "They were fed up with the McCanns, they wanted them to go away, but they weren't going away. They still had a missing child."
Gerry McCann, the father of missing Madeleine, has left a court in Portugal once again without being heard as a witness in the family's libel case against former police inspector Goncalo Amaral.
Mr McCann still does not know whether he will be able to give evidence as no decision has been taken.
Other legal teams are thought to have until October 16 to make submissions on his application, ahead of the judge making her final decision.
Mr McCann said, "Obviously it's disappointing, but we will just keep going."