The central question in this study is whether the power of the media agenda over the political agenda has recently increased. The agenda-building dynamics are established using cross-country time-series data on four issues, covering fifteen and eight years respectively of British and Dutch parliamentary debates and newspaper articles. Structural equation models show that the parliamentary agenda is more influenced by the media agenda than the other way around, and that the power balance has shifted even more in favour of the media. It is additionally found that media power is especially associated with issues within the European domain. This study contributes empirically to the 'mediatization' debate in a EU context, which is largely limited to the realm of theoretical speculation.