The Young Communist League of South Africa (YCL) says it will join the Treatment Action Campaign's (TAC) lawsuit against the government.
The TAC and displaced person Mahammud Hirsi filed an urgent application against the City of Cape Town and the Western Cape provincial government in the Cape High Court this week.
The application asks the court to order the city and provincial authorities to make "immediate" improvements to conditions at the city's camps for displaced people.
Now the YCL wants to join TAC's lawsuit and extend "the intervention to a national level" said YCL spokesman Castro Ngobese.
Ngobese said that legal action must be taken against the government on behalf of "all foreign nationals who were displaced and ... kept in refugee camps".
The YCL says "refugee camps are as terrible as concentration camps".
They have condemned police violence against displaced people who blockaded the R24 road to Krugersdorp last week.
"Displaced foreign nationals were treated in an inhumane and barbaric manner," Ngobese said.
Meanwhile, most displaced schoolchildren still have no access to education. They have not gone to school for almost three months.
Two weeks ago, provincial authorities told Sowetan that teachers would be sent to all camps. This was after camp residents said they reneged on a promise to provide transport for the kids.
But provincial education spokesman Paddy Attwell now says that only the Soetwater camp had been supplied with a teacher. Kids there are still waiting for Unicef to donate "lap desks", he says.
"We have not made any provision for chairs" he told Sowetan, adding that classes take place in a tent, and the kids sit on the ground.