Taking office in the National Congress in 2003, Dias switched parties to the PDT, and also spoke out against the proposal made by the Lula Government for social security reforms.

[4] He was later the lead member of the permanent councils on Agriculture and Rural Policies, and Education and Culture; and, in April he was chosen to compose the Parliamentary Inquiry Commission that was created to investigate supposed irregularities in the privatization of electricity, identified by the Tribunal de Contas da União (TCU) in the finances of the Brazilian Development Bank (BNDES) for the privatization of Eletropaulo.

In 2010, he became the vice-gubernatorial candidate in Rio Grande do Norte, on the ticket led by Carlos Eduardo Alves (PDT), but they were defeated by Rosalba Ciarlini.

[4] In 2014, Dias once again became a candidate for state deputy for the Union for Change coalition, made up of PMDB, PSB, PR, DEM, PDT, SD, and PROS.

[6] During the 2016 Natal municipal elections, Dias became a candidate for vice-mayor of the city, with long-time associate Carlos Eduardo Alves once again at the head of the ticket.