Madrid - As power changes hands in Spain's troubled Basque region on Tuesday, the confirmation of Patxi Lopez as the new regional prime minister will be overshadowed by the threat of violence from the militant separatist group ETA.

Security has been stepped up ahead of the parliamentary session that is due to elect Lopez premier, after ETA announced it would make it a "priority" to target the region's first government clearly defending its unity with Spain.

The recent arrest of ETA's military leader foiled a car bombing planned for Tuesday.

Graffiti threatening Lopez' Socialist Party have appeared in Basque villages, and the names of some of Lopez' future cabinet members were not revealed early on for fear of attacks before they were supplied with bodyguards.

Yet even if ETA's violence is expected to increase in the short run, there are also growing signs that its strategy of an armed struggle could be coming to the end of the road.

Lopez will end the political domination of the moderate Basque Nationalist Party (PNV), which has currents favourable to independence and had governed the region of
2.2 million residents since it was given a wide autonomy three decades ago.

The PNV won the regional elections in March, but the Socialists' unofficial alliance with the conservative People's Party (PP) will allow Lopez to form a minority government which is seen as heralding a new era.

On the national level, Spanish Prime Minister Jose Luis Rodriguez Zapatero's Socialists and the PP are at odds, but they joined forces to fight separatist potential in the Basque region.

During the 1939-1975 dictatorship of General Francisco Franco, many Basques saw ETA as defending Basque culture against Spanish oppression.

After Franco's death, however, the self-government granted to the region made ETA's shootings and bombings look increasingly absurd.

Even in radical separatist circles, 66 per cent of the Basques disapprove of ETA's violence, while only 2 per cent back it unconditionally, according to a 2008 poll.

ETA's shrinking support has run parallel with its military decline, with Spanish and French police constantly arresting members of the group.

ETA killed only four people in 2008, down from dozens annually in its heyday in the 1980s.

ETA, which has killed more than 800 people since 1968 to seek a Basque state created out of northern Spain and southern France, has been listed as a terrorist organization by the European Union and the United States.

Political parties linked to ETA have been barred from elections, a factor which has led many radical separatists to question the group's violent strategy.

Arnaldo Otegi, leader of ETA's outlawed political wing Batasuna, is seeking to unite a part of the separatist parties, trade unions and organizations in an attempt to switch from military to purely political methods in the campaign for independence, the daily El Pais said.

Otegi, however, described such reports as seeking to divide the separatist left.

Even ETA itself is now thought to be divided between those seeing armed struggle as hopeless and hardliners hoping to violently pressure the government into negotiations it rejects after a failed attempt in 2006.

Crackdowns on ETA will increase under Lopez, whose government is also expected to reduce separatist presence in the media and to promote the Spanish language alongside Basque.

ETA's decline, however, does not mean that of separatist ideas, with around half of the Basques voting for nationalist parties more or less inclined to loosen ties with Spain.

The PNV, which remains the biggest party, sees Lopez' taking office as almost a Spanish coup d'etat, with outgoing regional premier Juan Jose Ibarretxe describing his party as the "natural leader" in the region.

Lopez' term in office was likely to be "short and full of difficulties" despite his pledge to unite the Basques, historian Antoni Segura said.