Since 2005 she is a member of the municipal council of Solothurn[1] and in 2011 she was a candidate for the National Council,[4] but was not elected. 2012 she assumed as the president of the cantonal branch of the SP in Solothurn.[5][6] She was elected to the National Council in the Federal elections of 2019.[7] She was elected as the sole representative of the SP for the Canton Solothurn, as one was not re-elected.[7] In 2021, she resigned as the president of the Solothurn branch of the SP.[8] In October 2022, she announced her candidacy for the Council of States, the Upper House of the Swiss Parliament for the federal elections of 2023.[9]
In 2018, Franziska Roth defended the right of immigrant students to speak in their native language as in Egerkingen, a school demanded they speak in German also during the school breaks.[10]
As her party wanted to exclude men for the Federal Councilor elections of December 2022, Roth argued that everyone should be allowed to have a word in a democratic party.[11] But eventually the party only nominated women for the Federal Council as it already had a man to represent the party in the Federal council and the party sees itself as a supporter of gender equality.[11] Due to the Russo-Ukrainian war and as a member of the security commission of the parliament, she became much more aware of the necessity of a Swiss army.[12] She also argued that issues such as terrorism, cyber security or espionage should receive more attention from the Swiss army.[12]