What do you say if you're a steward of one of these unions, what do you say to your fellow workers, what would your position be?
So, I should say that I'm not a steward. That's partly because I don't want to be in a legal and policy position to ever be obligated to tell anyone to come in during a strike. However, I am in a workplace with multiple unions. When we have strikes, the first thing I do is begin talking to non-union workers and workers in other unions about not crossing picket lines. I always to try to propose collective ways not to come into work (all coming to the picket line together, for example, and calling in one after another). And, I've had success. And have taken shit from my union and management for it.
That said, I've recruited workers to join a striking union on the grounds that they want to strike but want legal cover. This isn't ideal, but if someone is joining a union so they feel they can strike, I'd rather have that situation than them coming into work.
On a related note, I was speaking to the PGCE student teachers at my school about not coming in on the last strike and was having success. Until, of course, the NUT sent them all letters telling them to come in