This article examines the inner unity of the European Parliament’s (EP) party groups prior to its first direct elections in 1979, at a time when such unity was technically not necessary, given the EP’s dominantly consultative role, according to the Treaties; and when no electoral incentives and few disciplinary tools could be used to enforce unity. Using semi-structured interviews with former Members of the EP (MEPs) from all EP party groups existing prior to 1979, as well as EP documents from that time, this article highlights, on the one hand, the positive and strategic incentives that group unity brought to individual MEPs. On the other hand, the article demonstrates the MEPs’ socialisation to group solidarity norms, their shared preferences and their personal connections. The article also suggests the role of MEPs’ attitudes towards European integration, and willingness to increase the power of their institution.
