In a surprise move, Delhi’s Lt. Governor Najeeb Jung, who had a running battle with Chief Minister Arvind Kejriwal, resigned on Thursday, without any reason, leaving the city and central government and most parties taken aback.

A brief statement released by the Lt Governor’s Office did not say why the 66-year-old former IAS officer had called it quits but quoted him as saying that he would return to academics, “his first love”.

In the statement, Jung thanked both Prime Minister Narendra Modi as well as Aam Aadmi Party (AAP) leader Kejriwal for their association with him.

The Congress questioned if a deal was struck between Kejriwal and Prime Minister Narendra Modi.

Delhi CM Kejriwal immediately telephoned Jung and later said his exit “is a surprise to me. My best wishes in all his future endeavours”. The central government, which appoints the Lt Governor, was equally taken aback.

Former Union Home Secretary Anil Baijal’s name emerges as the front-runner for the post of Lt Governor in Delhi.

Speculations are also rife that former Delhi Police Commissioner B.S. Bassi could also be among the choices for the post.

The central government, through the Lt Governor, controls Delhi Police, law and order and issues related to land in the capital. Earlier Kejriwal has repeatedly accused Jung of being “a Modi agent”.

The recurring Jung-Kejriwal battle was decided in favour of the former on August 4 by the Delhi High Court. The AAP government has moved the Supreme Court, where the matter is yet to be decided.