Besides, 15 PML-Q lawmakers have been included in new Premier Raja Pervez Ashraf's Council of Ministers taking its strength to 53.
66-year-old Elahi, who already holds the defence production and industries portfolios, has been appointed as the Deputy Prime Minister with immediate effect and until further orders, a notification issued by the Cabinet Division said last night.
The move will not confer on him "any powers of the Prime Minister in any manner whatsoever", it said.
President Asif Ali Zardari administered oath of office to another 15 ministers from PML-Q during a ceremony held at the presidency last evening.
Eight lawmakers were inducted as federal ministers while seven were inducted as ministers of state.
Sardar Bahadur Khan Sehar, Liaquat Abbas Bhatti, Sardar Talib Hussain Nakai, Sheikh Waqas Akram, Anwar Ali Cheema, Ghous Bukhsh Mehar, Jam Muhammad Yousaf and Chaudhry Wajahat Hussain took oath as federal ministers.
Rana Asif Tauseef, Malik Nauman Ahmed Langrial, Sardar Shahjehan Yousaf, Senator Saeed Khan Mandokhel, Chaudhry Ghias Ahmed Mela, Akram Masih Gill and Khawaja Sheraz Mehmood were inducted as ministers of state.
Prime Minister Ashraf, PML-Q chief Chaudhry Shujaat Hussain, Balochistan Chief Minister Aslam Raisani and Cabinet members attended the ceremony.