Frontrunners include Chrystia Freeland and Mark Carney, who are making the case they can guide Canada through domestic and international issues. At the top of the list: mounting trade tensions with the United States.

Canada's Liberal Party will announce Prime Minister Justin Trudeau's successor on Sunday as both party chief and head of the country's government in the midst of a trade war with the United States that could cripple the Canadian economy.

The new Liberal Party leader will have a colossal task at the top of his to-do list: defend Canada from Donald Trump.