Tunisia to vote on new multi-party technocratic government
It is likely that a majority of the legislature's 217 members will vote in favour of the line-up, making Chahed - at 40 -the country's youngest prime minister since it won independence from France in 1956.
But as Tunisia continues to find its bearings after the 2011 uprising that toppled longtime dictator Zine El Abidine Ben Ali, Chahed would also be the North African nation's sixth premier in less than six years.
Several speakers are expected to address the assembly and the vote is not expected before 9pm local time.
Chahed was appointed by President Beji Caid Essebsi early this month after lawmakers passed a vote of no confidence in premier Habib Essid's government after just 18 months in office.
On Saturday, Chahed - a member of Essebsi's Nidaa Tounes party - said he would head a 27-member cabinet which will also include 14 ministers of state, eight women "in important" positions and "14 young" ministers.
The premier-designate said on Wednesday that the line-up would remain unchanged despite reservations among several allied parties.
Chahed, a liberal who was local affairs minister before his nomination, should get around 60 votes from the Nidaa Tounes party from which he hails.
He should also be able to count on the votes of 69 lawmakers from the Islamist Ennahda Party, the largest in parliament.
Rached Ghannouchi's party said it had reservations over the line-up - in which it has three ministers - but said these would not prevent it from giving the proposed cabinet its vote of confidence.
Chahed may gain votes from the 24 lawmakers from the Al-Horra bloc, created after a split from Nidaa Tounes, and the 10 representatives from the liberal Afek Tounes party.
The vote on the new cabinet comes after Tunisia in January witnessed its worst social unrest since the 2011 uprising that triggered similar revolts across the Arab world during the Arab Spring.
While Tunisia is considered a rare success story of the Arab Spring, the authorities have failed to resolve the issues of poverty, unemployment, regional disparities and corruption that preceded Ben Ali's fall.
Chahed will also have to address security in the country after a wave of militant attacks, including two that killed dozens of foreign tourists last year.