MADRID (Reuters) - Spain's Supreme Court ruled on Sunday the newly formed "Bildu" alliance could not run in forthcoming municipal elections because of some candidates' ties to the political wing of armed separatist group ETA.
An official said the Court upheld by nine votes to six -- with one undecided -- a government appeal against Bildu contesting the polls after more than 12 hours of deliberations.
Bildu may appeal to the Constitutional Court against the ruling, which will be published in full on Monday.
"Bildu" grouped leftist Basque independence parties and unaffiliated activists after the Court denied legal status in March to "Sortu," a party relaunched as a successor to banned ETA ally Batasuna.
Unlike Batasuna, Sortu renounced violence and its launch followed a cease-fire declared by ETA in January, which the government swiftly dismissed as an electoral ploy.
The government broke off talks with ETA when the armed group broke a cease-fire in December 2006 by killing two in a bomb attack on Madrid airport.
"It (Bildu) is part of ETA's strategy," Interior Minister Alfredo Perez Rubalcaba said last week. "Some of its members have a direct link to the outlawed Batasuna."
Rubalcaba enjoys the highest rating of any minister in Spain's Socialist government due to leading a crack-down by security forces which has weakened ETA by arresting key leaders and uncovering several of their arms dumps.
Premier Jose Luis Rodriguez Zapatero's Socialists, however, are suffering from a sluggish economy and high unemployment and stand to lose major strongholds in municipal elections on May, an opinion poll showed on Sunday.
ETA have killed more than 850 people in shootings and bombings over the past half-century in a bid to carve out an independent Basque homeland straddling the Pyrenees.
The Basque Nationalist Party (PNV) put the central government under pressure last week saying its future support of the minority Socialists in key national parliament votes may depend on their support for Bildu to contest elections.
"For the PNV there is no justification for not allowing full political participation in the Basque Country," party leader Inigo Urkullu said.
ETA was formed more than 50 years ago during Francisco Franco's long dictatorship when local languages like Basque were banned and autonomy denied to many regions which had enjoyed it before the 1936-39 Civil War.
Basque, unique for its lack of links to other European languages, was revived after Spain returned to democracy in 1978 and regional autonomy was written into a new constitution.
Additional reporting by Inmaculada Sanz