New Delhi: AAP leader Atishi is all set to become Delhi's youngest Chief Minister after her swearing-in ceremony at Raj Niwas on Saturday evening at around 4:30 PM.

Atishi, who will be the third woman CM after Sushma Swaraj from the BJP and Sheila Dixit from the Congress , will be retaining four ministers from the Delhi cabinet including Gopal Rai, Kailash Gahlot, Saurabh Bharadwaj and Imran Hussain. Rai, Gahlot, Bharadwaj and Hussain are ministers in the outgoing Kejriwal government.

Besides, there will be a lone new entrant Mukesh Ahlawat, who is a first-time MLA from SC reserved seat of Sultanpur Majra.

"The oath ceremony is expected to be held late Saturday afternoon or in the evening, after all the formalities are completed," the officials said.

Aam Aadmi Party (AAP) sources claimed that the ceremony may be held around 4.30 pm on Saturday.

There was, however, no clarity if Atishi will take oath along with her council of ministers.

The swearing-in ceremony is likely to be a low-key affair as the mood in the party is not upbeat because of Kejriwal's resignation and also because of the delay in approvals, leaving little time for preparations said an AAP leader.

After Kejriwal tendered resignation as Delhi chief minister along with the council of ministers to Lieutenant Governor (LG) VK Saxena on Tuesday, files of both the resignation and government formation by Atishi were sent to President Droupadi Murmu for her nod, proposing September 21 as the date for the swearing-in ceremony, the officials said.

Sources claimed the notifications for the formation of the government and oath were expected to be received by the LG office late Friday night or the next day.

The AAP MLAs met earlier this week and unanimously chose Atishi as the leader of the ruling legislature party.

Kejriwal, the AAP national convener, walked out of the Tihar jail on September 13, spending over five months there in an excise policy case.

In a surprise announcement two days later, Kejriwal said he would resign in the wake of BJP 's "mudslinging" against him over corruption. He would return to the post of chief minister after getting a "certificate of honesty" from Delhi people in the upcoming assembly polls, he said.

(with PTI inputs)