The committee–floor relationship
Committee stage is where EU legislation is shaped: rapporteurs draft, shadow rapporteurs negotiate, and a working majority is assembled before the text reaches plenary. In theory, the plenary simply endorses the committee's work. In practice, things are more complicated.
We analysed 847 plenary votes on committee-originated reports in the 10th Parliament to date. In 23% of cases, the plenary vote outcome — measured by amendment acceptance rate — diverged materially (>10 percentage points) from the committee recommendation. We call this "committee-to-plenary drift."
Predictors of drift
The strongest predictor is amendment volume: files with more than 200 amendments tabled in plenary are 2.4 times more likely to drift than low-amendment files. This makes intuitive sense — high-amendment files signal political contestation that was not resolved in committee.
The committee with the highest drift rate is LIBE (civil liberties), at 34% — reflecting recurring plenary rebellions on migration and surveillance files. BUDG has the lowest at 8%, suggesting budget files are more tightly whipped.