After BN's failure in GE14 to remain as ruling government albeit his own success to retain Bera consituency for the forth term consecutively, Ismail had for the first time contested the Vice President in the subsequent 2018 UMNO leadership election and won with the highest votes ahead of Mahdzir Khalid and Khaled Nordin. On 20 December 2018, he was tasked to carry the duties of party Deputy President, while the incumbent Mohamad Hasan, performs the acting President during the over six-month "garden leave" by UMNO President Ahmad Zahid Hamidi.[25][26] He was appointed as the Leader of the Opposition in Parliament in 2019 when Ahmad Zahid Hamidi stepped down.[27]