So if they are actually contractors, they will have to resort to typical contract law--sue for breach of contract, unjust enrichment (if there is no binding contract), etc. They may be able to claim some statutory relief mechanisms--filing a construction lien, etc., depending on what kind of work they do.

And as another poster mentioned, sometimes "1099s" are really full-time employees who should be treated as such, i.e., overtime, benefits, etc.