Lucy the elephant has lived at Edmonton's Valley Zoo for more than 30 years. (CBC)

Animal rights activists hope an Alberta judge allows a lawsuit on behalf of Lucy the elephant to proceed.

Since 2007, animal rights groups have maintained the aging elephant who lives Edmonton's Valley Zoo is suffering and should be moved to a sanctuary in the United States.

But the city, which owns the zoo, argues Lucy receives the best possible care and the move could kill her.

City lawyer Steven Phipps argued before a Court of Queen's Bench civil hearing Tuesday that the case brought by PETA and Zoocheck Canada should be thrown out because the animal rights groups would be abusing the legal process if the suit was allowed to proceed.

Phipps argued that if there were any violation of animal protection laws, provincial enforcement officials would have taken action already.

"We meet or exceed all regulatory standards. That has been the consistent message of the city," Phipps said.

"The applicants don't agree with the standards, they feel the standards should be higher. That is their position but that is not what the law requires and so the city's position is Lucy is well cared, for Lucy is well treated [and] the city complies with all applicable regulatory standards."

But high-profile Toronto-based lawyer Clayton Ruby, who is arguing on the activists' behalf, said Lucy is suffering and needs to be moved to a warmer climate.

Ruby said Alberta and the Humane Society have already said they will not get involved in Lucy's case.

"The provincial authority issues the licence," Ruby told CBC News Tuesday.

"There's no reason why they would prosecute somebody they've just given a licence to because if they wanted to correct those errors they'd simply say and 'The licence has now got conditions, fix this, take her out of her suffering,' and they haven't.

"So we think that we've established that no one else is likely to bring this application on behalf of Lucy." Justice John Rooke reserved his decision.

Lucy's plight has become a magnet for celebrities, including Bob Barker, William Shatner and Margaret Atwood, who have urged the zoo to let Lucy move to the sanctuary.

With files from The Canadian Press.