The mother of missing Madeleine McCann is expected to attend a Portuguese court for the start of the family's libel action against a former local police chief.
Kate McCann will be accompanied by her mother Susan Healy for the first hearing of the case against Goncalo Amaral who published a book making allegations about the three-year-old's disappearance.
The McCanns have strongly denied the accusations and say the former detective's claims have damaged the hunt for Madeleine and exacerbated the anguish suffered by her relatives.
Their lawyer Isabel Duarte is expected to set out the case - on behalf of Mrs McCann, her husband Gerry and their twins Sean and Amelie, now eight - at Lisbon's civil court.
Mrs McCann, who is travelling to Portugal for the hearing, could have been called as a witness but is not expected to give evidence. Instead, a number of relatives will appear in the witness box. They will give evidence relating to the "damage" caused by Mr Amaral's book which, they claim, poisoned public opinion in Portugal against the family and allegedly deterred people from hunting for Madeleine.
The family stands to gain around £1 million in damages if their legal action succeeds. Spokesman Clarence Mitchell said: "Kate and Gerry McCann remain very confident that they will win the case. They have a strong case against Mr Amaral. The matter is now in the hands of their lawyer as it goes through court."
It is understood Mr McCann will not attend the hearing and will instead stay at the family home in Rothley, Leicestershire, to look after the children. The doctor is believed to have work commitments which have prevented him from travelling to Portugal.
It is unclear which family members will give evidence but Mrs McCann's cousin Michael Wright will appear in court at some point during the legal fight. Private investigator Dave Edgar, who assisted with the search for the missing child, is also part of proceedings.
Mr Amaral, the detective who initially led the inquiry into Madeleine's disappearance, is expected to argue that under Portuguese law he is entitled to make the claims published in The Truth Of The Lie. The former officer was removed from the Portuguese investigation in October 2007 after criticising the British police. His book is still on sale in Portugal.
The libel case will be heard on Thursday and Friday. It will then be adjourned until next Thursday when the court will sit again for two days. A final hearing is expected on Friday 27. The judgment is expected to be deferred.