[actionfromafar]

You could try, but that would most likely be illegal and also fought tooth and nail by unions, which aren't as neutered as American unions. In Europe, sympathy strikes aren't Verboten like in the US.

[octo888]

Many countries in Europe have weak unions (eg Estonia, Lithuania, Latvia, Poland, Hungary, Bulgaria, Portugal, Czech Republic, Greece).

And there is no real EU (did you mean EU by "Europe"?) wide labour law

[Mindwipe]

It depends on the territory, there's no pan-Europe regulation on it.

Even when the UK was in the EU sympathy strikes were illegal (to a much greater extent than the US).