Chad's president, Idriss Deby, already pressured by international donors to uphold requirements for how to spend new oil revenue, now faces increasing internal pressure.
A dissident group of relatives, former close advisers, former top officials and soldiers signed a statement last week saying they had more than 300 armed men, who are preparing to fight Mr. Deby from their hideout in eastern Chad.
This followed several attacks by dissident soldiers on government bases to steal weapons and ammunition.
An analyst from the London-based group, Global Insight, Chris Melville, explains, the dissidents come from the same ethnic group as Mr. Deby. Mr. Melville says they have been disappointed that the government has not given more support to Darfur rebels in western Sudan, many of whom are from the same ethnic lineage.
"Fundamentally, there are ethnic Zaghawa elements within the regime who had hoped that Deby would provide more direct support to the Zaghawa-dominated rebel groups in Darfur," said Chris Melville. "However, because of Deby's connection with the regime in Khartoum, he has preferred to play the role of mediator in the conflict, in an attempt to balance the external demands on him coming from Khartoum, and the internal demands coming from members of his Zaghawa clan."
The dissidents say they are also impatient with Mr. Deby's failure to improve Chad, which ranks near the very bottom of the U.N. Development Index.
The former rebel leader, who took power with Sudan's help in 1990, faces increasing protests from students, as well. Mr. Deby, 53, suffers from poor health, and many Chadians wonder how long he is fit to stay in office. A constitutional change passed earlier this year allows him to seek a new term in elections scheduled for next year.
Meanwhile, Mr. Deby has also moved to change a law, written in line with a World Bank-funded pipeline, to stop earmarking oil revenue for social projects. Mr. Melville says that is not surprising.
"The problem for any of these such schemes is that as soon as the oil starts pumping, the leverage of the multilaterals over the government dissipates," said Mr. Melville. "That's the problem facing the World Bank now. Once the pipeline is built, they can't remove it. They can introduce some sanctions against the government, but the government is clearly pursuing the desire to modify legislation for short term interests."
In a speech in his hometown last week marking his 15th year in power, Mr. Deby said he would fight any threat to security and stability, an apparent reference to the dissidents' challenge.
He has replaced top Zaghawa commanders with southerners. But at the ceremonies, a military parade was called off, and several heads of state who had been invited did not attend.