We assess a country's influence on decision‐making in the Council not merely on the basis of the number of its votes, but based on a novel measure that also takes into account the voting behaviour of other countries. A country that is likely to receive support from other countries will be more influential than a country with more votes, but which tends to be isolated in its policy preferences. We apply the methodology to a novel dataset and use it to assess whether changes in voting weights in the Lisbon Treaty influence the odds of whether countries get what they want when decisions are taken in the Council. We show that large Member States are less successful in getting support from others for their positions, while the changes in voting weights increase large Member States' influence, but statistically significant decrease it only for a subgroup of small Member States.