Founded by Mohammed Uthman al-Mirghani II's Khatmiyya order and Ismail al-Azhari's urban nationalist Ashigga Party (est.

The government's proposal of an Islamic constitution thus making Sudan an Arab Muslim state lead to Colonel Nimeiry's 1969 coup d'état and the abolition of the parliament.

The basic intellectual underpinnings of the party since its general congress in late 1960s, are: democratic pluralism politically, a mixed economy economically, and the establishment of a secular country towards as "the only acceptable way for peaceful coexistence in a country with different components of ethnic, tribal, religious, intellectual and cultural aspects in order to ensure the principle of that 'The sole basis of rights and duties should be based upon the Citizenship alone'."

The party has long-standing relations with the Sudan People's Liberation Movement (SPLM) with whom it signed the Peace Deal of November 1988 in Ethiopia which was then opposed by the National Islamic Front (NIF).

[8] As a consequence of its stances the DUP has suffered continuous attempts to divide and weaken it by the Sudanese security forces and the ruling party of Sudan, which seem to have failed so far.