In 1999, Zimmermann and four other teenagers founded the youth party
PETO – Die junge Alternative (PETO - the young alternative). The name of the party refers to the Latin word
peto (in English: „I postulate“). Zimmermann became first president of this new party until 2004. The party could rise its results continually. In 1999 they achieved 6 per cent and three seat in the city council and 2004 they improved this result with 16,6% and seven seats. In 2004 he belonged to the
city council, too. Five years earlier, he had not been allowed to run for office, because he was not yet 18 years old. He was president of the city council group of PETO until 2006. He has been president of the board which controls for the town-owned companies since 2005. During the Monheim am Rhein city Council election PETO achieved 29,56% of the votes and twelve seats in the city council, only 108 votes less than the biggest party
CDU which gained twelve seats, too. During the mayor election which took place simultaneously, for which he was nominated as a candidate by his party in August 2008, Zimmermann gained 30,35% of the votes, which meant a
relative majority, enough to win, after the
two-round system had been abolished in 2007. == Works ==