Althin is since 2002 a member of the Swedish parliament where he is a substitute in the justice committee and constitutional committee. Althin is also a member of the executive board of the Christian Democrat Party. He is also often seen in the media, not only regarding cases where he is hired as a defense attorney but also as a commentator. Despite his position as an MP he has continued his law practice, the Anna Lindh-case has been his most time-consuming so far.