The foundation of a new party was controversial within the socialist movement, because Troelstra was seen as a bourgeois force who had destroyed the unity of the SDB and the socialist movement.
Pendirian partai baru ini menimbulkan kontroversi dalam pergerakan sosialis, karena Troelstra dipandang sebagai kekuatan borjuis yang telah menghancurkan kesatuan SDB dan pergerakan sosialis.