Protests, political pressure, media snubs and legal action have turned up the heat on Washington Redskins owner Dan Snyder over opposition to the NFL team's nickname, considered by critics to be a racist slur.

About 24 members of American Indian tribes stood in the rain outside Wisconsin's Lambeau Field before Sunday's game between the Green Bay Packers and Redskins, demanding a change of the visitor's nickname.

US Congress members have written to National Football League commissioner Roger Goodell urging a name change while prominent columnists and media outlets have also taken a stand against using the nickname.