Ex southern rebels, the Sudan People's Liberation Movement (SPLM), formed a coalition government with its former northern enemies following a peace deal last year which enshrines wealth sharing and democratic transformation.
But SPLM parliamentarians blasted the northern National Congress Party (NCP) earlier this month for trying to pass important laws about human rights and conduct of the armed forces as presidential decrees, which cannot be amended by parliament. They said it violated the new peace deal.
"I consider this as a victory for all, as a victory for the democratic transformation and the new system," Yasir Arman, the head of the SPLM parliamentary bloc said on Wednesday.
He said the decrees were now to be debated as bills, which parliament could amend.
NCP officials were not immediately available for comment.
One of the decrees gave police and army officers immunity if they used deadly force against civilians and allowed any of Sudan's tens of thousands of largely uneducated police rank and file to use live fire at their own discretion.
U.N. human rights chief Louise Arbour said last month that security services in Sudan operated in a "climate of impunity." Civilians are often arrested without charge and tortured, sometimes to death.
Another decree regulated the work of non-governmental organisations (NGOs) in Sudan, requiring them to place their funds in accounts run by the government and allowing them to be ejected or shut down if they publicly disagreed with government policy.
The NGO act has worried the many international and national groups working to rebuild the south and in the separate and ongoing conflict in the western Darfur region, where one of the world's largest humanitarian operations is being hindered by continued fighting.
Sudanese authorities already place stringent regulations on their work and last year they arrested two international aid workers from Medecins Sans Frontieres (MSF), after the organisation published a report detailing more than 500 rapes over a few months in Darfur, where more than 2 million live in miserable camps.
The charges, which included spying and destabilising society, were dropped weeks later but scared many NGOs into silence about the atrocities they were witnessing in the remote region.
Tens of thousands have been killed in three years of raping, killing and looting in Darfur, violence Washington has called genocide. Khartoum denies the charge but the International Criminal Court is investigating war crimes there.