On 26 September 2017, he appeared on behalf of former Tehelka Chief Tarun Tejpal in front of the Goa Bench of the Bombay High Court.
[21] Since his appointment, his arguments have aided the Supreme Court in clarifying the law concerning the Narcotics Drugs and Psychotropic Substances Act, 1985.
[22] The Supreme Court accepted his arguments that in determining the punishment under the legislation, the deciding factor would be the quantity and not the purity of the narcotic drug.
[23] Additionally, his arguments were also accepted by the Supreme Court to expand the scope of the Prevention of Corruption Act, 1988 for it to apply to deemed universities, which is seen as a departure from the plain meaning rule of interpreting criminal law.
[27] As Additional Solicitor General, Lekhi has appeared before the Armed Forces Tribunal to defend the challenge to the appointment of the Chief of Naval Staff (India), filed by Vice-Admiral Bimal Verma.
[33] Lekhi was the counsel for the Government of Uttar Pradesh in the alleged "hate speech" case against Chief Minister Yogi Adityanath, successfully arguing for the plea challenging the order of the Allahabad High Court dismissed.
[36] In a major success for the Central Government, the appeal was allowed clearing the Lieutenant Governor to administer the day-to-day functioning of the Union Territory.
[37] He was engaged by the Department of Customs in the proceedings against the wife of All India Trinamool Congress Member of Parliament Abhishek Banerjee, Rujira Naroola for obstructing officers from checking her baggage at the Kolkata Airport.
[45] He is invited to lecture on issues of legal and public importance whether it is the hanging of Afzal Guru[46] or the control of Hindu temples[47] or the question of philosophy or ideology like Mao.