This slogan was mentioned in an emotional, vague way, and unity became somewhat clearer and more defined. Although the call for unity still existed, the rights of both parties within the union became more defined, and the realization was achieved that the joint struggle of the Sudanese and Egyptian peoples was the only way to achieve that unity. It may be appropriate to suggest here that the extremists in both countries formed the constituent tools of this new outlook and understanding. Mr. Abd al-Rahman's ambitions, as I indicated, were purely political; he desired to gain consideration and power. It seems his ultimate goal was to gradually seek an independent Sudan in which he and his family would have complete political authority. However, this was not at all acceptable to his main rival, Mr. Ali al-Mirghani, who at the time showed no signs of political ambitions and was cooperating quietly with the government. Due to suspicions of the British secretly conspiring with the Mahdi's son to achieve his life's goal, al-Mirghani completely changed his stance during the 1940s and supported the extremists and their slogan calling for "Nile Valley Unity." The extremist position was also strengthened by the effective support it found in the growing Egyptian propaganda during the 1940s and early 1950s. The Egyptians had revealed their activities in Sudan to increase their influence and enhance their reputation, following the 1936 agreement, which left the door ajar for Egyptian infiltration. The Egyptians quickly realized that the Graduates' Congress, which they had dismissed as a British tool, was a genuine national organization. They therefore encouraged and generously supported its activities. In fact, the new Mahdists lost their influence in 1944 at the Congress, which had since been dominated by pro-Egyptian groups. The Egyptians offered the Congress numerous facilities in the social, cultural, and educational fields. This undoubtedly diminished the strength and reputation of the new Mahdism and its leader, Mr. Abd al-Rahman al-Mahdi. The Sudanese government, out of necessity, tried to counter this propaganda by initiating a constitutional reform program, such as the establishment of the North Sudan Advisory Council in 1947 and the Legislative Assembly in 1948. However, this was not enough for the nationalists, including the new Mahdists themselves, who insisted on their peoples' right to self-governance and self-determination. Mr. Abd al-Rahman was greatly frustrated by the British government's efforts to forget its commitments to ensure Sudan for the Sudanese, in exchange for revising the treaty with Egypt to reduce its military expenditures in the Middle East and secure its strategic interests.