Following the May Coup of 1926 censorship targeting opposition press and publications intensified. In practice, Second Polish Republic has been described as having "mild censorship". The censorship was carried by the Ministry of Interior. Printing presses had to provide an advance copy to the Ministry, which could order the publication to be stopped. The publishers were allowed to dispute the Ministry decision in the courts. Newspapers were allowed to indicate that they were subject to censorship by publishing blank spaces. It was common for publishers to skirt the law, for example by delaying the sending of the first copy of a book to the Ministry, which meant that many controversial books were sold in the bookstores before the Ministry censors made their decision. The April Constitution of 1935 did not discuss the freedom of press issue, which has been seen as a step backwards in the issues related to censorship, and a Press Law decree of 1938 introduced a provision which allowed Ministry of Internal Affairs to prevent the distribution of foreign titles. 1939 saw the controversial arrest of a publisher and journalist Stanisław Mackiewicz.