In 1996, Ibarra became a national deputy and Secretary of the FrePaSo block in the Chamber. In 1999 she was elected to the Senate. In 2000 she became a city councillor in Buenos Aires, taking a leading role in her brother's administration. In 2001 she was re-elected to the Senate. Since 2003 she has been a supporter of PeronistPresidentNéstor Kirchner.In August 2004, Ibarra proposed legislation to legalise abortion in certain circumstances. In 2007 she suggested legislative changes to permit same sex marriage.