Sudan's ruling generals and an alliance of opposition groups have signed an accord creating a transitional power-sharing body, after weeks of negotiations aimed at breaking the political deadlock that has gripped the country since the overthrowing of President Omar al-Bashir in April.

The two sides signed the document on Wednesday after intense overnight talks in the capital, Khartoum, over the details of an agreement reached earlier this month to establish a joint military-civilian sovereign council that will rule the country by rotation.

The Transitional Military Council (TMC) and the Forces of Freedom and Change (FFC) alliance are still negotiating over a much more contentious document, the constitutional declaration, which is expected to be signed on Friday, according to an African Union mediator.

According to the framework agreement that was reached on July 5, the new 11-member governing body will rule the country for just over three years, after which elections will be held.

It will have a total of six civilians, including five from the protest umbrella movement, and five military representatives. The body will be headed by a general during the first 21 months of the transition, followed by a civilian for the remaining 18 months.

'Obstacles to overcome'

Al Jazeera's Hiba Morgan said while the signing of the political accord on Wednesday was significant, "there are still a lot of obstacles to overcome", referring to the more controversial constitutional declaration.

"The political document doesn't mention what roles the sovereign council and the cabinet will have - that will be defined in the constitutional declaration, which is going to be the core of the transitional agreement," she added from Addis Ababa in neighbouring Ethiopia.

"There is also the issue of immunity. The TMC had asked for immunity for the members of the sovereign and executive council, which is something the FFC does not want because they largely represent the protesters on the streets… [who are] demanding justice and accountability.

"If they give in to that demand, there are concerns among the opposition coalition that they will lose their supporters on the ground."

On Tuesday, as the two sides held talks on the power-sharing deal, a key protest group said it opposed giving the military "absolute immunity" against prosecution for violence targeting demonstrators.

"We refuse absolute immunity that the military rulers have asked for," Ismail al-Taj, spokesman for the Sudanese Professionals Association, told reporters in Khartoum.

'Huge achievement'

The TMC and the opposition coalition have been wrangling for weeks over what form Sudan's transitional government should take after the military deposed al-Bashir on April 11 in the wake of months-long mass protests against his 30-year autocrat rule.

Protesters had remained in the streets following al-Bashir's toppling, fearing the generals intended to cling to power or preserve some form of authoritarian rule.

Long-stalled talks between the TMC and the opposition alliance collapsed after the deadly dispersal of a protest camp in Khartoum on June 3.

Direct talks were later revived after mediation efforts by the African Union and Ethiopia.

"The signing of the document is a huge achievement representing a very decisive step towards an all-inclusive agreement amongst all the forces in Sudan," Mohammed el-Hassan Labat, African Union special envoy, told reporters after the signing ceremony.

"It ushers a new era and paves the way for the upcoming step … [which involves] consideration and deliberations over the constitutional document for the transitional period," he added.

'Government for all'

Addressing the same press conference, TMC deputy head Mohamed Hamdan Dagalo, who is also the head of the Rapid Support Forces paramilitary group blamed by protesters for the June 3 crackdown, described the signing of the document as an "historic moment" for Sudan.

"It is a new era of partnership between the brave armed forces and our partners in the FFC alliance and the Sudanese people," he said. "This document is the fruit of the efforts of the Sudanese people and us, as well."

Opposition leader Ibrahim al-Amin, meanwhile, said the upcoming government will be for "all the Sudanese, without any discrimination".

"We have suffered enough from totalitarian dictatorial regimes that have enslaved the people and devoured our riches. It is clear from the attitude of the signatories of this document that they will address and deal with all the Sudanese people on equal footing, allowing each and every citizen to contribute in rebuilding our country."