Scotland Yard officers plan to excavate two sites near the Ocean Club apartments at Praia da Luz, and a third site on the nearby beach, it has been reported.
Her Glasgow-born father, Gerry McCann, 45, said he and wife, Kate, 46, were still "hoping for a happy outcome", but her parents will not fly out for the search.
The decision to dig up the land in the Algarve is believed not to have come from a specific piece of new information but as part of a routine police review by UK detectives into the case.
British police, who will use radar equipment to look for disturbed earth or potential evidence, are said to be hoping to find any pieces of information or clues that may have been missed by their Portuguese counterparts.
A friend of the McCanns said the police were not specifically looking for a body, but were hoping to rule possible scenarios out as well as find new information.
The source said: "There will be earth diggers everywhere and it will look very dramatic and it will be a heartbreaking and hugely emotional time for Madeleine's poor parents.
"Certain areas should have been searched properly way back by the Portuguese authorities but were not."
The latest Crimewatch television appeal for new leads on the hunt for Madeleine gave police fresh information and they are hoping the digs might provide further clues.