TORONTO -- Banning long-term expat citizens from voting in federal elections has no pressing objective that justifies infringing on their constitutional rights, two of them argue in new documents filed with the country's top court.

In their factum, Gillian Frank and Jamie Duong argue residency in Canada is not a substantive requirement for voting.

They also maintain Ontario's Court of Appeal, in a split decision, was wrong to uphold the ban on the basis of preserving the "social contract" between Canadians and their government.

Parliamentary debates show no reference to such a contract or to the idea that non-resident Canadians should be disenfranchised on the basis that laws passed by legislators don't apply to them, their factum states.

"Reliance on broad notions of social philosophy, without any evidence to elucidate their contents, is a dangerous approach when it comes to the denial of fundamental democratic rights," their factum states.

"Rather than solving or responding to a problem, the impugned legislative provisions appear to be a solution in search of a problem."

The Supreme Court of Canada is slated to hear the Frank and Duong appeal of their disenfranchisement in February. So far, Quebec and Nova Scotia have sought to intervene.

While the legislation theoretically affects as many as 1.4 million Canadians, figures show only a tiny number of them have made the effort to vote from abroad.

Nevertheless, their voices were prominent in the election that brought Liberal Prime Minister Justin Trudeau to office last October. Both Trudeau and other Liberals have promised to review the ban, a position the government repeated on Monday.

"We have committed to repealing a series of provisions in the Canada Elections Act that we believe are unsuited for a democracy that strives to encourage citizen engagement and broad participation in democratic life," Jean-Bruno Villeneuve, a spokesman for Democratic Institutions Minister Maryam Monsef, said in an email.

"We remain committed to reforming our democratic institutions so that they can be more reflective of the needs and aspirations of the people they serve."

Villeneuve gave no time frame, and expats, unhappy with the lack of any visible action, note the Supreme Court fight remains scheduled.

The legal case turns on sections of the Canada Elections Act, first enacted in 1993 but only strictly enforced under the former Conservative government of then-prime minister Stephen Harper starting in 2007. The provision strips most Canadians living out of the country for more than five years of their voting rights. An Ontario Superior court justice agreed in 2014 the ban was unconstitutional, but the province's top court quashed that decision.

"Their taxes go to Washington, not Ottawa," the majority Court of Appeal stated.

Not entirely true, the factum counters, noting many expats do pay taxes to Canada and the voting ban effectively makes them voiceless second-class citizens.

"The impugned legislation is based on irrational considerations," Frank and Duong argue. "While it is true that resident Canadians may be impacted by more Canadian laws, it is nonetheless also true that non-resident Canadians can be profoundly affected."

Frank and Duong, who live and work in the United States, maintain the five-year limit is arbitrary. Both left Canada for employment reasons like "many citizens in a globalized world," but retain deep ties to this country and plan to return.

Their argument to the Supreme Court leans heavily on the dissenting Ontario Court of Appeal decision last year in which Justice John Laskin said voting rights depend only on citizenship.

The factum also cites a 2009 decision by the South African Constitutional Court that expat citizens who take the trouble to participate in elections are demonstrating "their continued commitment to our country and their civic-mindedness from which our democracy will benefit."