Is it illegal for an employment agency to block a hire?
Although it sounds unfair at best for them to be able to do what they are doing, it is most likely within their legal rights to be able to tell another company that you are not eligible for hire, which in a nutshell is what they are doing.. Either way, the cost of hiring a lawyer will be much more than simply getting a new job elsewhere. The only way it would be worth it would be if you are extremely rich in the first place and could prove that they are doing something illegal, in which case you could help out alot of people who cannot fight something like this to be able to better the system.