Wikie, 23, and her 11-year-old son Keijo are currently held at Marineland Antibes, a marine zoo in southern France, where they were born and have been kept their entire lives. It closed in January.

An application to send them to the most likely rehoming destination - Loro Parque marine zoo in Tenerife - was blocked by Spanish authorities. Loro Parque is already home to four orcas, including one born last month.

Lori Marino, president of The Whale Sanctuary Project (WSP), said their site in Nova Scotia is "the only option left", as French authorities have not yet identified a location in Europe for orcas and rejected a move to a marine zoo in Japan.

Her group is bidding to rehome the orcas in the east Canadian province despite a previous offer being rejected by the French ministry for ecology earlier this year.

Animal rights groups want the orcas to be rehomed in a whale sanctuary where they will have more space to swim and will not be forced to breed or perform in shows.

Agnès Pannier-Runacher, the French ecology minister, said in February she was looking for a European sanctuary but a suitable site for Wikie and Keijo has not been secured yet.

"If you don't even have a site, you're years away from being a viable sanctuary," said Lori, adding that the WSP had already carried out environmental studies, water surveys and been offered a lease by Canada's department of natural resources.

Managers at Marineland said sanctuaries are a hypothetical that "will take years" to be built and with "no guarantees" the whales will be properly looked after.

They stressed that Wikie and Keijo "must leave now" for their own welfare, adding: "Marineland reaffirms the extreme urgency of transferring the animals to an operational destination."

Though Marineland has closed as a marine zoo business, they are still legally responsible for the welfare of the animals until they are rehomed. (BBC/ Loro Parque)