Tommy Douglas Predicted That Canada Would Return To A Two Party System

"I think that in time we will get back to a two party system. But it will be a two party system which will have a party right of centre and one left of centre but this will take a process of adjustment,"
Tommmy Douglas
NDP Leader
1968 Election Leader's Debate

What Mr. Douglas didn't indicate in his prediction was the 'process' that would see a return to a Canadian two-party system.

As I see it there are two possible ways that a new two-party system could arise:
1) The New Democratic Party and the Liberal Party could merge and create a new entitiy. (This is hard to imagine at the moment), (OR)

2) Right wing Libs would migrate to Harper (as occurred in 2011) and Progressive Libs would migrate to the New Democrats .. resulting in the dissolution of the old Liberal Party of Canada.