Unifor national president Jerry Dias says there was "no meaningful discussion" leading up to the 2 p.m. ET strike deadline today.
Dias says morning meetings with Bombardier related to protocol in case of a dispute, and didn't focus on contract negotiations for the 900 employees.
He says Bombardier wants to make changes to pensions and benefits that are unacceptable to the employees and are similar to demands that caused a brief strike in 2011.
A Bombardier spokesman says the company is "deeply disappointed" that the employees are on strike.
He says the company is focused on minimizing the potential impact of the labour disruption on its customers.