Institutional conditions for effective parliamentary oversight of European Union politics

The implementation of European Union directives into national law frequently triggers extensive parliamentary activities, especially if they are complex, salient, and conflictive. These activities can cause delayed transposition. The literature suggests that early parliamentary involvement may speed up the subsequent transposition process. In this article, it is argued theoretically and empirically shown that this hope is only fulfilled where parliaments are sufficiently strong. On the empirical side, the article looks at the effect of ex-ante scrutiny on the duration of the transposition of more than 650 directives in four weak parliaments as well as in four strong parliaments. It is found that an early involvement of strong parliaments may speed up transposition. By contrast, weak parliaments’ early engagement with EU directives may even cause a further delay of the transposition process.