The minister, Ali Larayedh, whose nomination has been endorsed by the ruling Ennahda Party, has also been rapped by the opposition for failing to ensure stability in Tunisia.
His nomination is expected to make the task of finding consensus and building a coalition with Tunisia’s other political parties more difficult.
The party chose Larayedh in an overnight meeting and was to present him to President Moncef Marzouki later Friday, said Moadh Ghannouchi, the son of Ennahda’s chief.
Tunisia was plunged into a political crisis after the assassination of a leftist politician two weeks ago. On Tuesday, Prime Minister Hamadi Jebali resigned after his own party rejected his proposal to form an apolitical government of technocrats.
The split between the party and Jebali was seen as a deep disagreement between the party’s hardline and moderate wings.
Larayedh also announced late Thursday the arrest of several suspects in the assassination of opposition lawyer Chokri Belaid, saying “rapid progress” had been made in the investigation.
Belaid was shot four times outside his home on Feb. 6, provoking days of unrest as many Tunisians held the government responsible for his death.