[yulaow]

Can't you just signal to authorities or unions that you were dismissed for that reason (that is not a "good enough" reason on my state) and basically fuck up the entire company considering that that guidelines document would come up in even the simplest investigation? This would put your employer in a weak position, so weak you can easily even blackmail him

[roel_v]

Have you ever held a real job? Because your understanding of EU employment law and practices sounds very naive, to put it mildly.

[honest_george]

You can always sue of course (there is no union in the company). But what would you gain by doing so? They might be forced to hire you again, in which case you can be assured you will never receive a raise and will generally not enjoy working there a whole lot.

You could even try proving you worked too many hours, but that's quite hard to do (a list of start and end times would surely not suffice).

Edit: Also, they will surely claim that they did not tell you to perform that overtime, and that in fact you did so without them knowing.