Many will have heard of terms like counter-terrorism and counter-intelligence. These are concepts used by intelligence agencies around the world. The former refers to identifying and arresting (potential) terrorists and the latter to identifying foreign spies.
Just as destructive to a free republican society as terrorism and espionage is, however, lobbyism. Therefore we introduce the idea of counter-lobbyism. The intelligence agencies of space settlements should treat lobbyists the same way as terrorists and spies: identify them and disrupt their evil practices. Since lobbyists usually operate in secret, intelligence agents are most suitable for counter-lobbyism.
Once illegal lobbyists are caught, they should be exposed – preferentially by standing trial in a public court of law. The penalty for foreign lobbyists should be a suspended prison sentence and deportation from the country and for domestic ones, a long prison term plus loss of the right to vote and to hold public offices.