The National Central Banks are responsible for liquidity operations with their counterparties, which can be any financial institution from an EEA country which has a counterparty status in the country of the NCB. This means that National Central Banks are active in the market every banking day.
Decision making by the Governing Council is supported by a web of ECB expert committees, working groups and task forces where a governor nominates a member. These bodies have no decision making power, but they serve as fora in which some differences can be ironed out and the groundwork laid for the Council.