Political conflict may involve the unethical placement, on one party's orders, of one or more of its adherents into another party's membership. Infiltration of political parties for the purposes of espionage and political sabotage is relatively easy in countries whose political parties rely heavily on volunteers, or whose treasuries are low. The political spy may work himself, or, by contributions, buy himself in. This is easier at local party levels, but once in at the local level the spy may be placed in a position of trust, or elected as an officer and thus have access to the higher echelons of party planning and personnel. Political infiltration may be associated with criminal acts of illegal entry, theft and illegal wiretapping.
Political infiltration is a tactic regularly employed by national communist parties in non-communist ruled nations, as has been witnessed in the UK, France, Italy and a number of other countries, where over many decades, communists have infiltrated socialist, social-democratic and liberal parties to attempt to move them to the Marxist extreme-left. In other countries, like the USA, excluding the activities of the communists, political infiltration is sporadic and short-lived at the election campaign times for the key offices of President, Senator, or Governor. In countries with a history of political instability, infiltration of the ruling party may be preparatory to coup or revolution.