Muslim leaders are angry that their community, thought to represent about half of Nigeria's roughly 130 million citizens, has provided only 165 of the 382 delegates to the National Conference on Political Reform.
"The federal government must increase the number of Muslim delegates in the national conference," demanded a statement issued by the Muslim umbrella group Jama'atul Nasril Islam (JNI) after a meeting in the northern city of Kaduna.
"If these demands are not met as soon as possible, we will ask the Muslim delegates to withdraw from the conference," the statement said.
President Olusegun Obasanjo called the conference in a bid to get representatives from around the country to re-examine the way Nigeria is governed after six tumultuous years of civilian rule.
The results of the conference will be put to parliament - or perhaps to a national referendum if some activists get their way - and may lead to modifications to the 1999 constitution.
Some activists are seeking a
change in the constitution
Obasanjo has faced down pressure from radical pro-democracy groups and some regional activists for a Sovereign National Conference with elected delegates who would be empowered to enforce root-and-branch reform.
Some observers warned that such a conference could unleash centrifugal forces of regionalism, tribalism and religious fundamentalism that could tear Nigeria apart or plunge it back into civil war.
More than one million Nigerians died of violence, disease and starvation during the 1967-70 civil war and thousands still die every year in political, ethnic and religious disputes around the country.
The religious divide, which splits Nigeria roughly into a Muslim north and a Christian south, has also overshadowed the start of the reform conference, despite its being dominated by hand-picked establishment delegates.
The JNI, speaking after a meeting of imams and regional chiefs chaired by the influential Emir of Gwandu, Mustapha Jokolo, said Muslims also object to the fact that both the conference chairman and its secretary are Christian.