TORONTO, March 31 (Reuters) -
* Canada's Unifor has filed application with the Ontario labor relations board for certification to hold unionization vote at Toyota plants
* Unifor president says expects vote to organize Toyota's Canadian plants to happen next week
* Unifor says expects unionization vote to start next Monday
* If organization drive successful, Unifor says will move to begin collective bargaining immediately
* Unifor says it is "absolutely confident" that it has enough support for certification, says not strategic to announce numbers (Reporting by Solarina Ho)