Hello, question about how a union organizing campaign will affect those on an E3 visa. Are Aussies employed at a U.S. carrier under the E3 visa given any sort of protection during a union organizing campaign? Can the employer arbitrarily cancel their employement contract as a result of an organizing campaign?

I'm not a lawyer, so that means you should really consult a lawyer.

But I would say, it's illegal in the United States for a company to interfere or punish union activities. It doesn't matter who is doing the organizing.

However, Aussies on E3 visas are dependent on the company continuing the sponsorship (my amateur understanding).

So there's nothing to stop the company from ending the sponsorship at any time, but it would look very suspicious if they just booted a few who happen to be union organizers and not the entire lot of them.

They could probably sue and might win, but would it be worth the hassle?

Definitely seek professional legal advice.