The teams have asked the Namibian Sports Council to impose the ban in support of their campaign for 40 per cent black representation in the national team, as well as the the resignation of Andries Wahl, the Namibian Rugby Union president, and a government commission of inquiry into all aspects of the running of the game.
Four black clubs recently withdrew from the 15-strong national league as the first part of their protest.
"White supremacy still maintains its stranglehold on rugby," a representative of the clubs said. "The concept of national reconciliation is completely foreign in Namibian rugby.
"Even during matches between black and white clubs, white referees discriminate openly against black teams. The whistle is used very effectively to ensure white dominance."
The NSC is expected to make a decision on a ban by the middle of this month.
"There is no need for a commission of inquiry as I know the history of rugby better than anyone in this country," Karl Persendt, the NSC chairman, said.
"I am a black man myself and a former rugby player and 22 years ago I was discriminated against. Nothing has changed.
"An international ban would be catastrophic for the sport but the current situation is not acceptable to the people of this country, nor to the government.
"If drastic change does not take place, we may have to close the doors and start anew."
Rugby union in Namibia, a country three times the size of Britain but largely made up of desert and semi-desert, is almost exclusively confined to the white Afrikaner and coloured races which make up approximately 12 per cent of the population of 1.8 million.
The NRU has only 900 registered players and is too poor to pay its representatives at the World Cup. Namibia are scheduled to meet France, Fiji and Canada in Pool C in France in October.
"We will participate at the World Cup unless we are restrained from doing so by our government. We don't disagree with the demands, just with the time frame," Wahl said.
Namibia have been preparing for the World Cup by playing in a South African provincial competition which excludes the top 120 players on Super 12 duty. After seven rounds, they have yet to win a match.