I was with the company for 10 years, as a member of bargaining unit. I was accommodated m with the unions blessing to non bargaining. I had no choice but to ssign the letter terms of employment , they said they would fire me , if I did not, so basically I signed it to keep my job.

Is this grounds for a constructive dismissal if I lose my new job ?

If you loose your new position (or the company dismisses/lays you off) you would be entitled to severance and I would strongly encourage you to give us a call and have one of our employment lawyers provide you with a free consultation (1-844-661-9065).

In the meantime, I would encourage you to visit the severance pay calculator our firm has created to see what you would be owed if the Company terminates/dismisses you (www.SeverancePayCalculator.com).