EDMONTON — The Supreme Court of Canada could be getting involved in the battle over the fate of an ailing elephant in an Edmonton zoo.

Animal rights groups are seeking leave to appeal to the high court in their ongoing fight to have Lucy the elephant moved to a warm-weather U.S. wildlife sanctuary.

PETA and Zoocheck have applied to challenge an Alberta Court of Appeal split decision last month that ruled against their plan to sue the City of Edmonton over Lucy.

One of the appeal court justices wrote a dissenting opinion, saying the groups should have public standing in the case and it should go to trial.

In their Supreme Court application, the groups say private citizens have a right to seek legal remedies to ensure that governments enforce animal protection laws.

"Every day that Lucy spends at the Valley Zoo, her condition continues to deteriorate," Jeffrey Kerr, a lawyer for People for the Ethical Treatment of Animals, said Wednesday.

"By denying our standing to sue, the court has given Lucy a virtual death sentence, so we hope the Supreme Court will reverse the appeal court's short-sighted decision and reinstate the case."

The City of Edmonton plans to oppose the leave to appeal application.

Lawyer Steven Phipps says Lucy at 36 is a middle-age elephant with manageable health problems. Phipps says the elephant is being treated for arthritis, which isn't unusual.

He says moving her could threaten her well-being.

"If you place Lucy under a stressful situation, she develops a fairly significant breathing issue," he says.

"One of the most stressful situations for an elephant is moving them. They are not easy animals to move. They are very large. It is quite a process."

Phipps says the animal rights groups are trying to argue the merits of their original case, which will not be before the Supreme Court if leave to appeal is granted.

The city will also argue that the case is not of national importance.

He says the case will be about the process the animal rights groups can use for answering the questions they want to put forward.

A Court of Queen's Bench judge ruled last year that the case was an abuse of process, and two of the three appeal judges agreed. They said provincial legislation sets out how captive animals should be treated, and it's up to animal welfare officials to enforce those laws.

"They tried at the Court of Queen's Bench, they were unsuccessful, they tried at the Court of Appeal, they were unsuccessful. Now they are trying the Supreme Court," Phipps says.

Affidavits from veterinarians filed on behalf of the animal rights groups say Lucy suffers from arthritis, obesity, foot infections, dental problems, bed sores and chronic respiratory issues.

They say the causes for some of her ailments are the concrete floor of her indoor enclosure, Edmonton's freezing cold winters and the fact she has lived alone for half her life.

Over the years celebrities have supported the cause for moving Lucy, including former talk-show legend Bob Barker and actor William Shatner.

They say she needs to be moved so she can live in peace with other elephants in her final years.