In 1979, upon his graduation from law school, Juncker became president of the Christian Social Youth Organization, which is an arm of the PCS. Party leaders quickly noticed his talent for organization and willingness to make decisions. When he was 25, they made him parliamentary secretary of the PCS, a position that allowed him to see the workings of the party from the inside and to come to know its leaders well. In 1984, Juncker was elected to the Chamber of Deputies, and in that same year, at age 29, he became minister of labor. Although trained in law, he excelled in analysis of economic and financial problems, and gained a reputation for intelligence, energy, and directness. His straightforward manner and practical approach to problem solving won him allies in the business as well as the political community. A succession of important government positions followed.
He was reelected to the Chamber of Deputies in 1989, and was appointed to head both the labor and the finance ministries by Prime Minister Santer. He was reappointed to these same posts after the PCS's electoral victory of 1994. In 1990, Juncker was elected president of the PCS. This administrative position allowed him to consolidate his political base and to direct the development of party policies on all issues of importance. Jean-Claude Juncker replaced Jacques Santer as prime minister on 26 January 1995, becoming the youngest head of government of any EU state. Juncker survived the 1999 election by joining forces with the Democratic Party (DP).