A referendum that will ask people living in Ukraine's Crimea region whether they want to join the Russian Federation is "way outside the parameters of legitimacy," according to a leading Canadian authority on international and constitutional law.

University of Ottawa professor Errol Mendes says that, since the referendum in Crimea will take place while Russian troops control the region, few countries, including Canada and the United States, will view the referendum results as legitimate.

He says it also violates the Charter of the United Nations.

"Essentially, it is a referendum under the force of military power," Mendes told CTV's Canada AM on Thursday.

Russia has taken control of the strategically important Crimea region in Ukraine after the country's pro-Russian president, Viktor Yanukovych, was deposed following months of protests. Russia has an important naval base in the region, and since the majority of the population in Crimea are ethnic Russian, Russian President Vladimir Putin has said that sending in his military is necessary to protect them.

But Mendes says it's not just the presence of Russian troops in Crimea that makes the referendum, slated for March 16, so questionable.

"It's is in violation of the sovereign power who should be controlling the territory: Ukraine," he said. "When Quebec conducted referendums, two referendums in the past, our Supreme Court has basically said ‘Because we are a democratic country, we will not allow unilateral succession.'"

He said Canada's Supreme Court has made it clear that if Quebec votes to secede, the province has the right to enter negotiations with the rest of Canada.

No such stipulations are in place for the Crimea referendum.

Mendes said the upcoming referendum in Scotland, which will ask citizens if they want independence from Britain, is also different from what will take place in Crimea.

"The question was actually determined in cooperation with the British Parliament," he said. "In addition, there is a clear path forward by Great Britain and Scotland as to what will happen if there is indeed a ‘yes' vote."

Citizens in Crimea will not actually be able to vote "no." Instead, they can vote "yes" for one of two options: either join the Russian Federation or revert back to Crimea's 1992 constitution.

According to Keir Giles, an international security expert at the London-based think tank Chatham House, the 1992 constitution "refers to the Republic of Crimea as a 'Soviet state' and describes it as a sovereign entity that grants Ukraine only such powers as it sees fit."

"In other words, the restoration of this constitution would be a step toward notional independence under Russian control," Giles wrote in a blog post on the Chatham House website.

This has led many commentators and observers to sum up the Crimea referendum as this: Either join Russian now, or grant Crimea the authority to join Russia in the very near future.

There's no option to keep things as they are.

What makes this even more problematic, Mendes says, is that that a large percentage of Crimea's population are not ethnic Russians.

"Yes, the majority of people in Crimea are Russian speaking and are ethnic Russian. But they are only 60 per cent," he said. "There are another 40 per cent which are either Tatars … or Ukrainians. And the way the referendum is being structured, it makes clear they will have very little say in it."