A Senate vote on the government's plan to legalize pot is expected to move the bill forward Thursday evening in Ottawa but uncertainty abounds over whether travelling and absent senators could allow the Conservatives to snuff out the bill.

Travellers to Canada will be routinely asked whether they are bringing marijuana into the country as Ottawa moves to legalize recreational pot use.

"If you're asked if you smoked marijuana, that is not a question that you are obliged to answer at a U.S. port of entry."