Spain's Constitutional Court ruled late on Tuesday that a seven-year jail term imposed on the party's executive committee for collaboration with terrorists was disproportionate and anti-constitutional. The Supreme Court sentenced them in 1997 after the party had broadcast a pro-Eta video.
The decision to jail the 23 party leaders - one was later freed on health grounds - followed a year of Eta attacks on local conservative politicians, including Miguel Angel Blanco, whose murder in July 1997 prompted Spain's biggest anti-terrorist demonstrations.
Basque nationalists still condemn the sentence. "That has now been proven to be a clearly political verdict," a Herri Batasuna spokesman said yesterday. But the government said the case showed the opposite. "The rule of law works regardless of who you are," a spokesman said.
The Basque political landscape has been transformed since the men were sent down: Eta's armed separatists called a ceasefire last September while Herri Batasuna reconstituted itself as Euskal Herritarok (Basques Together) and began peace talks with Madrid.
There was speculation yesterday that the release of the 22 might prompt Eta to declare its ceasefire permanent. Freedom of Eta prisoners has long been the main demand of Basque separatists, to which the conservative government in Madrid has made only grudging concessions.
Euskal Herritarok won 20 per cent of the Basque vote in regional elections last October, an endorsement of Eta's more conciliatory approach.