The decision by Spain’s Prime Minister, José Luis Rodríguez Zapatero, to release a notorious Basque separatist killer on hunger-strike will herald one of his most difficult periods in office since coming to power nearly three years ago.

Iñaki de Juana Chaos, who is being force-fed after refusing to eat for 114 days, will not walk the streets quite yet. After he is released from hospital in the Basque Country, where he has been sent today from Madrid, he will serve out the remaining year of his sentence for making threats at home under police supervision.

For relatives of Eta’s victims, however, the fine details of the move will be irrelevant. They will see Mr Zapatero’s Government as having caved-in to the blackmail of terrorists and are sure to mount furious protests in response. De Juana completed an 18-year sentence for his role in 25 killings two years ago. He is now in prison for making veiled threats in two newspaper articles written from prison.

Parallels are often drawn between the four-decade-long Basque conflict and the situation in Northern Ireland, but the differences are perhaps more illuminating. Spaniards are far more concerned about Eta than ordinary Britons ever were about the IRA, even at the height of its bombing campaign on the British mainland.

Victims of the Basque separatist group’s 40-year campaign of violence are also organised into a powerful political force in a way that was not seen in Britain. The Association of Victims of Terrorism has become one of Mr Zapatero’s fiercest opponents and is able to organise street protests that draw hundreds of thousands of supporters.

The opposition Popular Party has been preparing an all-out assault on the Prime Minister over the issue, drawing on a wellspring of public outrage that a man convicted of participating in 25 killings should walk free after just 20 years in jail.

So why is Mr Zapatero doing it? In a sense, both the Government and Eta are stepping back from the abyss. They know that the death of De Juana would trigger a new cycle in the conflict at a time when it had seemed headed for extinction. In one of his greatest political gambles, Mr Zapatero appears to have decided to weather the political storm for some weeks in order to prevent the conflict from being extended another generation.

The peace process seemed dead on December 30, when Eta broke its nine-month ceasefire and exploded a huge bomb at Madrid airport, killing two Ecuadorean immigrants. Mr Zapatero broke off talks with Eta, but the Opposition suspects that back-channel contacts continue behind the scenes.

Since then, however, Eta and its political allies have made a series of shifts in their position, apparently desperate to return to negotiations. Though the Government does not say it, there is a feeling that the bomb may have represented the last desperate act of a hardline faction in Eta. If so, there are signs that it has proved as fatally counterproductive for the remaining radical elements of Eta as the Omagh bombing in 1998 was for the Real IRA.

For Eta's political allies, the group's December 30 bomb was an unmitigated disaster. It ended their hopes of participating in May local elections and showed they had little or no influence on the gunmen. It took days for the group to issue an equivocal and highly contradictory statement, saying it had not intended to kill anyone and oddly insisting that its “permanent” ceasefire was still in place.

In an interview with The Times last month, De Juana backed the peace process, saying it was “more necessary than ever” after the December bombing. But there are no signs that Eta wants him to take up a role now he has been released. Anti-terrorist officials apparently believe that Eta long ago tired of De Juana’s antics and see him as beyond their control.

An obvious question is: where does De Juana go now? He insists he is no longer a member of Eta and has said he would dedicate himself to his writing if freed. But he is unlikely to fade into obscurity in the Basque country. Far Right figures have threatened to kill him if he is ever freed and many Basque towns will not want such a notorious figure in their midst. He may be forced to live in a sympathetic country such as Cuba or Venezuela.

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