In a brief statement in Parliament broadcast live on Spanish television, José Luis Rodríguez Zapatero said: “The Government is going to initiate talks with Eta. The process is going to be long, tough and difficult.

“We’ll handle it with determination and prudence, with unity and loyalty and always with respect to the memory of the victims.”

He added: “Democracy is not going to pay any price to get peace.”

It is the first time that a Spanish Government has openly held peace talks with the group. Previous Spanish Governments have taken part in secret negotiations.

The announcement was condemned by Mariano Rajoy, the leader of the conservative opposition Popular Party.

Señor Rajoy, whose party broke off relations with the Government recently over holding talks with Eta, said: “We cannot give our support to the process which the Government has opened because they have not completed the conditions to start talks with Eta.

“For 30 years the majority of Spaniards have wanted to finish with Eta and regain the freedom which they have denied many millions.”

Victims’ groups also attacked any negotiations with Eta. The Association for the Victims of Terrorism said in a statement: “If Eta has murdered almost 1,000 people, Zapatero has killed their memory. This is one of the saddest days in the history of the democracy.”

Other parties support the peace process.

Eta announced its first permanent ceasefire in March, and it is widely expected that its banned political wing, Batasuna, will be legalised later this year to allow it to join all-party talks. Eta has killed 817 people since it began its bloody campaign 38 years ago for an independent Basque country in northwestern Spain and southwestern France.

In recent years the arrests of leading Eta members have greatly weakened the group, which has not killed for more than three years.

A general revulsion against Eta after 9/11 and the Madrid train bombings also drained it of much of its support.

Since the ceasefire, police and secret service assessments of Eta have convinced Señor Zapatero that the group wanted peace.

He was able to make his announcement of public talks after a change in the law last year when the Spanish Parliament voted to give the Government permission to begin talks with Eta if the group ended its armed campaign.

Spanish Governments have held secret talks with Eta ten times since the death of the dictator General Francisco Franco in 1975.

An opinion poll showed for the first time that Spaniards are less worried about terrorism since Eta’s ceasefire.

The poll, for the Centre for Sociological Investigations, found that Spaniards placed Eta and terrorism in fifth place in a list of concerns after unemployment, immigration, crime and housing.

Only 19 per cent said Eta was their biggest worry.

Times Recommends

• Would you live on the wrong side of the Berlin Wall?
• Wish you were here, says Iraq tourist board
• Russian policeman’s corruption plea to Putin