Prime Minister Atal Bihari Vajpayee and his deputy Lal Kishenchand Advani are likely to attend the swearing-in ceremony of the Gujarat chief minister, which is likely to be Narendra Modi, in Gandhinagar on December 18, Bharatiya Janata Party sources said on Sunday.

Meanwhile, party president M Venkaiah Naidu, party in-charge of Gujarat and national treasurer Ramdas Aggarwal and party general secretary Sanjay Joshi will leave for Ahmedabad on Monday for the meeting of the newly elected BJP legislators.

"It [Modi's election] is only a formality," Naidu said after a meeting of senior office-bearers with Vajpayee.