She subsequently joined the Democratic Party of the Left and in 1999 she became head of the women group of the Democrats of the Left.
During the general election in 2001 she was elected at the Chamber of Deputies.
On 17 May 2006 she was nominated Minister for Equal Opportunity during the Prodi II Cabinet, working on DiCo bill, with the Minister of Family politics Rosy Bindi.
Since 23 May 2007 she has been a member of the National Committee for the Democratic Party.
On 7 May 2017, Pollastrini has been appointed Vicepresident of the Democratic Party, representing the left-wing of the party.