Exiled with Saad Zaghlul to the Seychelles in 1921-1923, Nahhas was chosen upon his repatriation to represent Samanud in the first Chamber of Deputies elected under the 1923 Constitution.

His wife was said to have great influence on him, and is alleged to have played a big role in spoiling the friendship between Mostafa el-Nahhas and Makram Ebeid.

Nahas fell out with his patron, Makram Ebeid who was serving as the Finance minister and expelled him from the Wafd and the cabinet at the instigation of his wife.

[3] Ebeid retaliated with The Black Book, a detailed expose published in the spring of 1943 listing 108 cases of major corruption involving Nahas and his wife.

[3] Ebeid accused Nahas of having the Egyptian embassy in London buy expensive silver-fox fur coats for his wife with government funds; of confiscating a school in the Garden City area of Cairo to turn into his personal office; of using government money to irrigate land in the desert owned by his cousin; and of abusing his position as prime minister to pressure landowners in the Nile delta to sell farmland to him.

[3] Against Madame Nahas, Ebeid accused her of engaging in insider trading on the Alexandria cotton exchange and of pressuring her husband to appoint members of her family to high offices of state that they were not qualified for.

[5] Caffery called Nahas a venal "street politician" whose only platform was the "tried and true formula of 'Evacuation and Unity of the Nile Valley'" and stated the only positive aspect of him as prime minister was that "we can get anything which we want from him if we are willing to pay for it".

[7] Nahas passed a law forbidding Egyptian farmers to grow wheat, which would done something to reduce the food shortages and the consequent inflation, as he and his wife personally benefited from the high international prices for cotton.

In a bid for popularity amid rumors that King Farouk was planning to dismiss him, on 17 October 1951 Nahas unilaterally abrogated the 1936 Anglo-Egyptian treaty, making himself the hero of the hour.

[10] The police commander called the Interior Minister, Fouad Serageddin, Nahas's right-hand man, who was smoking cigars in his bath at the time, to ask if he should surrender or fight.

[11] The Ismailia incident outraged Egypt and the next day, 26 January 1952 was "Black Saturday", as the anti-British riot was known, that saw much of Downtown Cairo, which Khedive Ismail the Magnificent had rebuilt in the style of Paris, burned down.