The man whose eventual entry into the government is commonly said to be the key to President Jaafar Nimeri's "national reconciliation" policy stared out at the stars from his rooftop garden and said, "The answer is no."

Not "no" to national reconciliation, said Sadiq Mahdi, grandson of the Mahdi the Great whose armies killed British Gen. Charles "Chinese" Gordon in 1885 in the battle of Khartoum, but "no" to becoming prime minister - or any minister for the matter.

"I see many satisfactory roles outside executive politics and I do not think being in office and ordering people about is real power," he said.

"That is a very superficial vision of power. I want to influence things."

No one here doubts that Sadiq, as he is called throughout Sudan, is influential.

But there is an air of paradox about the man, who at 41 remains elegant as ever in immaculate white turban and gown, surrounded by similarly clad retainers in his mansion.

Prime minister at 30, deposed, jailed, exiled, convicted of plotting to overthrow the Nimeri government in 1975 and again in 1976 at the head of his fanatical Moslem Ansar warriors, Sadiq in theory remains condemned to death, although the sentence was handed down when he was abroad.

Since he came back to Suden late last summer at Nimeri's behest, Sadiq has failed to arrange the return of some 4,000 Ansars from Ethiopia or as many as 3,000 living in Libya.

It has not been for lack of trying - either by the government or Sadiq - for Nimeri undertook major reconcilation efforts with both Ethiopia and Libya which have yet to pay many visible dividends.

Even so, Nimeri may still be content. For the return of Sadiq in itself capped a long effort for Nimeri to legitimize his government.

Since coming to power with Communist help in 1969, Nimeri has gotten rid of his leftist image, ended a 17-year civil was with the largely Christian and Animist south and is close to restoring political harmony so long absent from Sudan.

Even having Sadiq in Omdurman, the twin city across the Nile from Khartoum, the capital, is a safer bet than worrying about him plotting from abroad.

For now, Sadiq is reportedly more concerned with selling Nimeri's national reconciliation to the Ansars inside Sudan than persuading those in Libya and Ethiopia to return.

The Ansars are a radical, even revolutionary, Islamic sect, reputed to be more inclined toward revenge than reconciliation.

Still, Sadiq has not attended sessions of the central committee of the Sudanese Socialist Union, the only legal party, although he and other prominent opposition leaders were appointed to it following in elections in February.

Sadiq feels that the elections - part of the price Nimeri paid for getting him to return - were "relatively free under the circumstances."

Of the 274 parliamentary seats, analysts believe that as many as 140 were won by opposition candidates - enough, according to some opposition leaders, to upset the Socialist Union.

Sadiq's friends in what once was the Umma Party won some 30 seats as did candidates affiliated with the former National Unionist Party, a largely middle class, urban obranization.

The elitist Moslem Brothers took about 20 seats and between 40 and 60 seats were won by independent local dignitaries.

In the elections for the semi-autonomous southern region - the six-province predominantly black area established at the end of the civil war in 1972 - almost all the local ministers lost.

Nimeri got the message and appointed Gen. Joseph Lagu, leader of the southern Anyanya rebels during the civil war, to run the southern region cabinet. His cabinet is made up of men who had been either in jail or in the political wilderness.

Nimeri, on paper at least, has won over to the virtues of national reconciliation everyone but the remnants of the once influential Communist Party and the Ansar splinter group led by Sherif Hindi, who remains in defiant exile.

Hassan Abdalla Torabi, once secretary general of the radical rightwing Moslem Brothers and recently appointed a Sudanese Socialist union, central committee member, summed up the mood: "There's an air of freedom and we are hoping to bring new life to the S.S.U., open it up."

Proof, of sorts, was provided a few days ago with a series of slowdowns and strikes, which theoretically are illegal. "That would not have happened - people wouldn't have dared - even a year ago," a shopkeeper said.

After years of civil strife and political instability, it is perhaps too early to be optimistic. The economic situation is messy and shows no signs of rapid improvement.

But Nimeri seems to be in better shape domestically than ever before.