The International Whaling Commission (IWC) has convened in Morocco for a five-day meeting that is expected to lift a 24-year-old ban on whaling.
The ban was imposed after many species were hunted nearly to extinction.
The move to resume legal whale hunts comes as scientists and conservationists say new evidence shows whale intelligence is in many ways as sophisticated as that of humans.
For decades, opponents of whale hunting have used several arguments to push for a total ban on killing the creatures - saying that they are too rare and endangered, or simply too beautiful.
Now scientists and ethicists are advancing a new argument: Whales, they say, should be accorded legal rights, just like people.
Tom White is a professor of ethics at Loyola Marymount University in Los Angeles and a long-time advocate for whale and dolphin preservation.
"The most important right that would be involved is the right not to be killed, and the right not to be owned as a piece of property," he says.
When humans consider whales and dolphins, he says, they must realise that "there is a who there, not a what. This isn't an object, this is a being; this is a person, not property".
Scientific research steadily accumulated over the past 30 years shows that whales are self-aware, can solve complex problems, communicate with each other on a sophisticated level, and even show grief at the loss of offspring or a close companion.
Whales, many scientists say, have a culture all of their own.
Richard Ellis is a whale expert from the American Museum of Natural History in New York. He says: "There is no question that cetaceans - that is, whales and dolphins - certainly have the highest level of intelligence of any mammals on earth, probably higher than human beings, although [it is] very, very difficult to measure it."
In May, an international gathering of scientists in Helsinki, Finland, issued a declaration calling for non-human rights for cetaceans.
Japan, Norway and Iceland are the only remaining countries that hunt whales commercially and the IWC is now expected to approve limited numbers of whale kills over the next ten years.
But countries including Brazil, New Zealand and the UK say they will fight the plan to lift the 24-year-old ban.
When it was introduced, the ban was championed by Ronald Reagan, the then US president. But now, conservationists are outraged at Barack Obama, the current US president, for breaking his campaign promise to end whale hunting.
Instead, the Obama administration is leading the effort to lift the ban, allowing countries once more to legally slaughter whales.
"What I find especially disappointing," White says, "is that he is not looking at the most important scientific data. His position is ethically untenable in the face of the scientific data."
The US administration says the deal will actually spare thousands of whales by preventing the three whale hunting countries from cheating on quotas and exploiting legal loopholes. Japan kills thousands of whales each year in the name of so-called scientific research.
But conservationists do not buy that argument. They say enough is now known about the creatures to make whale killing as morally abhorrent as murder.
Ellis says: "It's as if a spaceship came down to earth and some strange looking creatures popped out, and we took a look and said those are really weird creatures, we can't communicate with them, I know, let's kill them and eat them. And that's what we've done."