ALGIERS - After more than a decade of bloodletting in Algeria that has left at least 150,000 people dead, a controversial blueprint for peace sponsored by President Abdelaziz Bouteflika is to be put to a referendum on Thursday.

Bouteflika has campaigned hard to elicit support for his Charter for Peace and National Reconciliation, whose highlights include an effective amnesty for many of the armed Islamic militants who rose up after the army cancelled a 1992 election their politicians were poised to win.

The president argues that his plan offers the country its only hope of achieving peace and thereby attaining social and economic development.

Algeria's political opposition and human rights groups have urged the electorate to reject the charter on the grounds, claiming it does not turn the page on years of catastrophic violence but sweeps it under the carpet.

Algeria's opposition Socialist Forces Front (FFS) has called for a boycott of the referendum, arguing that it "cannot endorse a text that glorifies force and deprecates political mediation, consecrates impunity and amnesty, and in the end negotiates away pain and suffering".

The independent League for the Defence of Human Rights (LADDH) has dismissed the referendum as "scandalous and absurd", claiming "nobody has a right to vote no".

"We're not against peace and reconciliation, but we do oppose this charter since we don't think it will bring peace," LADHH President Abdennour Ali-Yahia, a lawyer, said of the text.

The charter's text, which some have criticised as overly vague, would end legal proceedings against detained, exiled or fugitive Islamic extremists "who have already halted their armed activity and surrendered to the authorities".

The government estimates there are about 1,000 armed extremists, whose aim is to install an Islamic state, still at large in Algeria.

Only "those involved in mass massacres, rapes and bomb attacks in public places" would be excluded.

The charter reads: "the sovereign Algerian people ... mandates the president of the republic to take all steps necessary to implement the measures".

For Ali-Yahia, this would mean "the head of state will be able to rule by decree and curtail all liberties by claiming that this charter is a people's mandate."

Earlier this month, Bouteflika told a rally in the northeastern region of Kabylie that there was "no alternative solution" to the proposed charter.

The head of state enjoys support from parties forming the "presidential alliance" as well as from the unexpected quarter of the Trotskyite Workers Party.

The charter also paves the way for compensation to be paid to "victims of the national tragedy," including families of the "disappeared", those arrested by security services and never seen again.

The LADHH estimates these to number 18,000 people, while the official human rights commission says they number 6,000.

"They were taken away and killed by the security services across the country. So, the order must have come from the military leadership," said Ali-Yahia.

Bouteflika launched a "civil reconciliation" initiative at the start of his first five-year term in 1999, leading to a partial amnesty for thousands of Islamist rebels who laid down their arms.

The program was endorsed overwhelmingly in a referendum in September that year, and Bouteflika was reelected in 2004, largely because the peace initiative helped quell the fighting.