In 2003, the African National Congress nominated him to be one of their representatives in the National Council of Provinces, the upper house of the South African parliament in terms of a political agreement between the ANC and NNP.
[1][2] After the 2004 general election, Adams was reappointed to the NCOP as the NNP's sole provincial delegate.
In October 2004, ANC chief whip Mbulelo Goniwe announced that eight NNP MPs, including Adams, would cross the floor and join the ANC during the floor-crossing period in September of the following year.
[4] After the composition of the Western Cape Provincial Parliament was reconstituted following the floor-crossing period, Adams officially became an ANC representative in the NCOP.
[5] In November 2006, Adams voted for the Civil Union Bill which legalised same-sex marriage in South Africa.