I agree the headline is misleading. > by choosing to form a union for an essential service they’ve contractually agreed not to strike. Putting up scaffolding

I agree the headline is misleading. > by choosing to form a union for an essential service they’ve contractually agreed not to strike. Putting up scaffolding for an oil-drilling company isn't an "essential service". The agreement not to strike is in the collective bargaining agreement their union negotiated for them. First you form a union; then you can sign up for collective bargaining. I don't know how "strike" is defined in Canada; but declining to do overtime in the UK would be referred to as a work-to-rule. I don't know the terms of the collective bargaining agreement; maybe it mentions witholding labour, rather than strikes. At any rate, it seems to be wildcat action, and I imagine it will undermine the union's negotiating position. If you take wildcat industrial action, you can't expect the union to stand up for you when the employer comes after you with lawyers.