In 1959, he founded the Finnish Rural Party (Suomen Maaseudun Puolue), which was succeeded by the True Finns in 1995.
When his opponent, Urho Kekkonen, was elected president of Finland, Vennamo broke off his Agrarian League affiliation.
and catchphrases, some of which became popular terms such as "the forgotten people" and rötösherra (a pejorative for corrupted politicians).
In the 1968 presidential election, he negatively surprised President Kekkonen and his centre-left allies by getting 11% of the votes.
After the 1983 elections, the Rural Party was allowed to join the government, but Vennamo preferred not to become a cabinet minister.