An Ontario Superior Court begins hearing a challenge today of a law that strips some Canadian expatriates of their voting rights.

The law affects Canadians who have lived abroad for more than five years.

Gillian Frank and Jamie Duong, who live in the U.S., launched a legal challenge against the federal government two years ago.

They say the rule in the Canada Elections Act is arbitrary, unreasonable and should be struck down as unconstitutional.

Frank, a history professor at Princeton University in New Jersey, says he has deep ties to Canada and plans to move back when he can find a suitable job.

The federal government has argued the current law helps strike a balance between the democratic rights of Canadians while ensuring sufficient ties exist between a citizen and Canada.

The rule was imposed in 1993, but wasn't enforced until 2007.