Vitoria, Spain  - The Basque regional government Wednesday approved a controversial plan for a referendum on the self- determination of the northern Spanish region, which was expected to set it on a collision course with the Spanish government.

Voters in the region of 2.1 million residents will be asked whether they would like to see a negotiated end to the violence of the militant Basque separatist group ETA, if it expresses a willingness to lay down arms, regional Prime Minister Juan Jose Ibarretxe explained.

Voters will also answer the question whether they would approve of talks between the Basque political parties on the region's right to decide its own future.

Ibarretxe believes that an open discussion on Basque self- determination would help to solve the problem of ETA, which has killed about 820 people in four decades, but analysts in Madrid have described his plan as secessionist.

Spanish Prime Minister Jose Luis Rodriguez Zapatero's government regards a regional referendum as illegal, and was expected to take legal action to prevent the vote from taking place.

If the Basque regional parliament approves the draft law on June 27, the referendum would take place on October 25, according to Ibarretxe's plan.

The law does not include an explicit condemnation of the violence of ETA in order to win it the approval of the separatist party PCTV, whose nine legislators were expected to determine the outcome of the vote in the 75-member regional parliament.

If the plan was approved in the referendum, the Basque parties would draw up an agreement on the region's "right to decide," which would be submitted to a new popular vote by the end of 2010.

Ibarretxe admitted that the October referendum would not be legally binding, but said it would have a "political and democratic" validity.

The Basque region already enjoys a wide autonomy, but sectors within Ibarretxe's Basque Nationalist Party (PNV) would like to see it obtain a status close to independence.

Zapatero's attempt to negotiate with ETA collapsed in December 2006. The group has killed six people since then. Its most recent victim, police officer Juan Manuel Pinuel, was killed in the car bombing of a police barracks on May 14. (dpa)