Lobbyists
A lobbyist is a person who works to influence political and administrative decisions. The word comes from "Lobby" - an entrance area or a hall in a Parliament where lobbyists can meet politicians.
According to an EU code dating from 1994, lobbyists should identify themselves carefully, inform people about their interests, not misuse their connections with the EU institutions, respect confidential information, abstain from giving false information and selling official documents, avoid professional conflicts and not pay people employed by the institutions.
Since 1996, the EU Parliament has had its own rules for lobbyists that have to be respected if the lobbyist wishes to have access to EU Parliament buildings.
There is no official register of all of the lobbyists working in Brussels. There are certainly more than 10,000. One source has suggested that there are some 14,000 in 3000 different lobby groups.
Notes
In the EU, most lobbyists are commercial lobbyists, representing firms and economic organisations, whereas half of the lobbyists in Washington, USA, represent non-economic interest organisations.
Links
http://www2.europarl.eu.int/lobby/lobby.jsp?lng=en