Gillian Frank and Jamie Duong, who live in the U.S., were shocked to learn of the five-year rule when they tried to cast their ballots in the 2011 federal election.
In an effort to combat what they see as an affront on their citizenship, the pair launched a legal challenge against the federal government nearly two years ago, arguing the rule in the Canada Elections Act is arbitrary, unreasonable and should be struck down as unconstitutional.
"Having a say in the government, having my full citizenship reinstated is absolutely vital to me," Frank told The Canadian Press in an interview ahead of the three-day hearing, which begins Monday in Ontario Superior Court.
"I believe the Canadian government continues to affect me and it will affect me when I return home one day."
Frank, a history professor at Princeton University in New Jersey, moved to the U.S. in 2001 to get his PhD and stayed on as his studies led to a job.
Despite living in the States for years, the 35-year-old, who grew up in Toronto and served in the Canadian military, said he has "deep ties" to Canada.
He follows Canadian news closely, visits regularly and plans to move back when he can find a suitable job.
"I've applied to every Canadian job available in my field but there's been less than 10 of those," said Frank. "The moment there's a job in Canada that I get in my career I would snatch it."
The federal government has argued the current law helps strike a balance.
"The five-year rule was established as a way to balance the democratic rights of Canadians while ensuring sufficient ties exist between a citizen and Canada, as well as the citizen's intention to eventually return to Canada," said a spokeswoman for the Minister of State for Democratic Reform.
The rule was originally enacted in 1993 amid debate about the strength of expatriates' ties to Canada and how well informed they were about the domestic political situation.
However, it was only in 2007 that Elections Canada began to enforce the rule.
Until then, the five-year clock would reset for expats who returned even for short visits. Now, they have to "resume residency'' before leaving again to regain their right to vote abroad.
Some long-term expats, such as members of the Armed Forces and diplomats, are exempt.
For Duong — an Ithaca, N.Y., resident who remained in the U.S. because he can't find the job he wants in Canada — the rule and the reasoning behind it seem archaic.
"That argument may have worked back in the days of steam ships and before the advent of mass communication the way we have it now," said the 30-year-old who was raised in Montreal.
"My ties to Canada are incredibly strong. I am in communication with people there on a near daily basis. I keep up with what's going on there and the fact that my place of residence right now is outside of Canada doesn't mean that I don't care what happens in Canada."
In fact, Duong argued, living abroad for years can make a person all-the-more aware of being Canadian.
"When you're outside of Canada people see you first and foremost as a Canadian and you identify first and foremost as a Canadian," he explained.
"I think that it's very important for all Canadians to have a voice in our democracy, regardless of where they happen to be living."
The charter challenge has the backing of former chief electoral officer Jean-Pierre Kingsley, who urged in 2005 for the rule to be scrapped — a view adopted unanimously by a parliamentary standing committee.
Lawyer Shaun O'Brien, whose firm took on the case, believes the issue affects a growing number of Canadians — she currently estimates about 2.8 million — who live abroad.
"With globalization what we have is this increased movement. And a lot of the reason that Canadians move outside the country is for employment," she said."It's not appropriate to say that in order to exercise your full fundamental democratic rights you have to curtail your employment."
The case had led to a number of expatriate Canadians coming forward with concerns similar to Frank and Duong's, said O'Brien.
"If people feel that strongly about Canada and wanting to vote...why would we not want to have their participation in the country," she said. "Why would we want to limit such a fundamental democratic right that people hold so deeply."