At least 28 people, mostly members of the security forces, have been charged with trying to overthrow Sudan's government in a coup.
Turabi has denied his party's involvement in a coup plot
State prosecutors accused them of declaring war on the state, planning to assassinate political leaders and cut communication links.
AFP news agency reports that they are members of the Islamist Popular National Congress of Hassan al-Turabi.
Several of the suspects are from Darfur, the prosecution says.
A retired police colonel is accused of recruiting security officers from Darfur to carry out the plot.
President Omar al-Bashir has said the Popular National Congress can resume its activities if it disowns Mr Turabi but this was rejected by PNC members.
Mr Turabi who was jailed in March in connection with a previous alleged coup, denies any involvement with the coups, or links to the rebels.
However, he says he sympathises with some of their demands, such as decentralisation of power from the capital, Khartoum, to impoverished regions such as Darfur.
Mr Turabi was once a close ally of President Omar al-Bashir but he lost out in a power-struggle between the two in 1999.
Since then, he has spent several years in prison.
The BBC's Alfred Taban in Khartoum says that following all the talk of coup plots, Khartoum residents are becoming increasingly apprehensive.
The presence of well-armed military men on many roads in the capital is frightening people.
Some people claim to have been mishandled during the many searches being carried out by the armed forces, he says.