SPAIN: The human rights group, Amnesty International, has warned that Spain risked "undermining fundamental freedoms" by banning demonstrations in favour of the Basque pro-independence party, Batasuna.
Judge Baltasar Garzon of the High Court has suspended all Batasuna operations for three years.
He alleges it is part of the armed group ETA, which is blamed for more than 800 deaths in its long campaign for Basque independence.
Batasuna denies it is ETA's political wing.
Judge Garzon has also banned any demonstrations to protest against his decision.
Meanwhile, the Spanish government has asked the courts to ban Batasuna altogether.
However, a pro-Batasuna protest is due to be held in the northern Basque city of Bilbao at the weekend.
"Ahead of Saturday's demonstration in support of the suspended grouping Batasuna in Bilbao, Amnesty International urged the Spanish and Basque authorities to ensure that fundamental rights to freedom of expression and peaceful protest are not undermined by recent legal moves that appear to prohibit such protests," the group said in a statement.
Amnesty International said it recognised Spain's right to ensure safety and that it had "repeatedly and unequivocally condemned ETA's continuing campaign of killings of civilians".
"However, ETA's abuses must not be used to justify undermining fundamental freedoms," it said.
The Basque government banned similar protests last weekend, citing concerns over violence.
But even if it approves the march, Judge Garzon could attempt to prohibit it, as he did for a similar pro-Batasuna march in the Navarre region last Friday.
Spain's National Police broke up that small protest once it started.
However, Basque police relented when about 1,000 pro-Batasuna demonstrators defied the local government's ban and took to the streets of San Sebastian last Sunday.
The Basque regional premier, Mr Juan Jose Ibarretxe, said he supported the police decision to back off because breaking up the march would have required physical violence.
Leaders of Spain's ruling Popular Party (PP) were outraged.
They claimed that the Basque government did little to ensure freedoms for hundreds of PP politicians who live under threats from ETA and require 24-hour bodyguards.