The members of the Transport union currently sympathy striking in the harbors don't dictate what's allowed to be imported, there's just no-one that's willing to unload cars of this specific brand before the ship has to leave again - there's a difference. Tesla could try to import them by other means, if they can find a way that does not need any intervention by labor that is. The argument that dockworkers single-handedly is deciding what is allowed to be imported is false to begin with and the number of members in that specific union is therefore irrelevant.

So far there's five different unions (I think) who's about the join the strike because this conflict affect the whole of Sweden, so to calculate how many individuals that are currently involved and actively support these actions you'd have to include all electricians, maintenance workers, postal service employees and so on as well (the list is growing rapidly).

As the pressure will be incrementally increased until Tesla realize that they have the whole nation against them you would pretty soon have to include the full 70% of the working population to calculate how many individuals that are actively supporting this action.