"Our merchants and masters complain much of the bad effects of high wages in raising the price and lessening the sale of goods. They say nothing concerning the bad effects of high profits. They are silent with regard to the pernicious effects of their own gains. They complain only of those of other people.”

― Adam Smith, An Inquiry into the Nature and Causes of the Wealth of Nations

There are no laws against the masters organizing

there is: anti-monopoly laws, anti-cartel laws etc