Let me elaborate on some things that indicate that the UCI is the union. You, and probably the other professional cyclists, are not aware that the UCI has a standard contract between the riders and the teams. Any dispute which arises between the two is automaticaly governed by the standard contract and at the same time must be disputed in front of the UCI as they have control over a three month sallary insurance. Since the Pro Tour was created, the UCI has even more power due to the new contract stipulations involving doping investigation clauses. If you don't want to sign away all of your rights to the UCI, then you don't race as a professional. Those are your options, and as I read other discussions here I am surprised at how poorly informed most are in regards to the complexity of the situation.
Having read what I wrote I must restate what position I believe the UCI to be taking. A union, generally, is an organization in which it is optional to participate and serves as a median between the employer and the employee. However, in this case the UCI is more like a monopoly run as a dictatorship. It is not optional weather or not to join the UCI, and in contract negotiation and dispute resolution, they serve as the union and the court respectively.
For example, I was employed by the Mercury team in 2001 when there were problems with money starting in May. According to the rules, after 30 days of non payment one could request a payment from the UCI bank guarantee and follow some administrative process to be paid. I learned quickly that the UCI has no regard whatsoever for the riders when it took more than two years to get the money. Of note was one particular incident where after several months of following the procedure to be paid, a letter was sent to the UCI informing them that if they didn't respond to our requests we would look into other processes for getting the money.
We promptly recieved a fax, signed by Hein Verbrugen, telling us that those tactics may work in the USA, but that they are in Switzerland, and that he was going to inform his colleagues to deal with us accordingly in the future.
Clearly his "colleagues" understood, and then, more than a year went by when I was asked by a Cycling News reporter if I or the others had been paid. I explained to him that we had been following the procedures and were still waiting for some kind of response, and then I noted that the UCI had not followed its own rules or the dispute would have ended a year ago. Within a few hours of the article being posted I received an email from the council at the UCI (copied to Lance Armstrong, Johan Bruyneel, Jim Ochowitz, and Tim Maloney the journalist) informing me that if I didn't retract my statements within 48 hours they would use their right to suspend me until some resolution could be agreed upon. Of course, the pressure from the other recipients left me no option but to call Verbrugen himself and to retract the statement. So, I guess, "union" is not the right word, but no one would risk a fight with the UCI by starting a union, or for that matter even joining one.
Landis, 22-Dec-2006; the UCI had no love of Landis for public complaints about failures of the UCI to protect rider interests.
In 2008, the UCI is claiming to be the protector of those interests from the nefarious ASO.