After being elected into the first chamber of the Riksdag, Trygger gained a reputation as a good debater with deeply conservative values. He was a member of the committee of 1895-98 that was formed to revise the terms of the union with Norway. In 1909, Trygger became leader of a conservative group in the first chamber. When the rightist wings joined together in 1913 to form the National party of the first chamber, Trygger became the leader of a united rightist force in Swedish politics and as such he opposed the new influences of democracy and parliamentarism in the 1910s. His rival as conservative leader was Arvid Lindman, the main character in the more moderately conservative rightist party of the second chamber of the Parliament of Sweden.