リトアニア社会民主党
Butkevičius was born at village in Radviliškis district municipality. Since 1992 he is member of the Social Democratic Party of Lithuania (LSDP). He was chairman of the LSDP in the department of Vilkaviškis in 1995–1997, deputy chairman of the LSDP in 1999–2005 (re-elected in 2001), and chairman of the LSDP since 2009.