Based on a new database containing all the amendments proposed on all the executive bills debated in the Spanish Parliament from 1996 to 2019, this paper explores the impact of multilevel politics on parties’ legislative behavior. We look at the effects of regionalization, a highly controversial issue, and Europeanization, a traditional consensual one. Results show that the regional cleavage significantly influences their amending activity. Both regionalist and statewide parties propose more amendments on bills that touch on the interests of the regions, and this is especially the case when regional affairs are politicized. On the contrary, the increasing saliency of EU affairs during the euro crisis did not affect the number of proposed amendments on EU related bills, not even among soft euro skeptical radical left parties. Europe is not a relevant political cleavage but our empirical findings challenge the idea that in a country without party conflict on European integration EU related bills are not disputed. The paper concludes by exploring the consequences of the findings on ongoing debates on legislative behavior.
