JUBA, Sudan - Former rebels in southern Sudan have withdrawn their members from a national coalition government, party officials said on Thursday, to pressure their northern partners to reignite a stalled peace process.

"The SPLM (Sudan People's Liberation Movement) has recalled all ministers and presidential advisers from the government of national unity," SPLM Secretary-General Pagan Amum told reporters in the southern capital Juba.

Amum said the National Congress Party (NCP), the SPLM's former foes and the dominant party in the coalition, had failed to carry out key parts of a 2005 peace agreement.

"Presidential advisers, ministers and state ministers will not report to work until these contentious issues are resolved," he said after a week of intense talks.

The NCP had used its majority of 52 percent of government and parliament to continue a one-party state, Amum said, and he expressed concern at unconstitutional actions and rights violations by the dominant party.

"The (SPLM) condemns...unlawful detention of political opponents...censorship of the press and harassment of journalists...expulsion of diplomats without consultation," he said listing just a few grievances.

The peace deal ended Africa's longest civil war and created a coalition government in Khartoum, with the SPLM taking just over a quarter of the posts.

It shared wealth, enshrined democratic transformation and paved the way for elections by 2009 and a southern referendum on secession. Decades of conflict had claimed 2 million lives and drove 4 million from their homes.

The decision by the SPLM, the political wing of the southern rebel movement which fought the Khartoum government for more than 20 years, is the culmination of months of disagreement between the two main partners in the national government.


NOT QUITTING GOVERNMENT

Yasir Arman, a SPLM deputy secretary-general, said the party was not quitting the government and lines of communication would remain open. Parliament would continue and Salva Kiir would remain in his post as first vice president.

"We hope that we will resolve this crisis," he said in Khartoum. "The National Congress Party (NCP) created this crisis and Salva Kiir is ready to resolve it."

The SPLM formed a high-level committee that will work on unresolved issues of the deal, such as demarcating the north-south border, redeployment of northern troops from southern oil fields and creating an administration for the oil-rich Abyei area.

The NCP has expelled Western diplomats, aid workers and even the head of the U.N. mission in Sudan in recent years. It has also detained some 25 opposition figures without charge for weeks, contravening Sudanese law.

One of the main northern opposition parties, the Umma Party, said the SPLM move would force the hand of the NCP.

"This is the ultimate thing that could have been done, it's very serious, it's very positive, and the NCP has to respond in a responsible way," spokeswoman Mariam al-Mahdi said.

The failure to implement the north-south deal may hinder peace talks in Libya this month on Sudan's western Darfur region because rebels doubt the NCP's willingness to talk seriously.