Albertans vote today on whether to begin the path to quitting Canada as Mark Carney warns against a 'Brexit'

Alberta holds the lion's share of Canada's proven oil reserves, which are the fourth largest in the world. Voters are being asked to decide between staying in Canada and moving to a second, binding independence referendum. Polling suggests most Albertans favour remaining, but Trump's threats have fuelled anxiety over national unity.

Premier Danielle Smith has stopped short of backing secession, leaving her open to attack from both camps.

The vote has exposed deep rifts, among them divisions within the separatist movement itself.