Islamabad, April 9 : Pakistan Prime Minister Shehbaz Sharif castigated President Arif Alvi for returning the Supreme Court (Practice and Procedure) Bill, 2023, unsigned and calling him a worker of the Pakistan Tehreek-e-Insaf (PTI), according to a media report. The bill is aimed at curtailing the powers of the chief justice - including the suo motu and the formation of benches. The PTI has strongly condemned the move to pass the legislation and said it is an "attack on the judiciary", Geo News reported. "President Alvi returning the Supreme Court Bill duly passed by Parliament is most unfortunate," the prime minister said in a hard-hitting tweet hours after the president returned the bill to the legislature, Geo News reported. The president has, since the formation of the Pakistan Democratic Movement's government in April last year, returned bills and also refused to administer the oath to several members of the federal cabinet, including Prime Minister Shehbaz. Alvi has sought the advice of PTI Chairman Imran Khan - who was ousted as the prime minister in April last year - on several crucial matters, including the appointment of the chief of army staff. In the tweet, the prime minister said the president has belittled his office through his actions as he follows the PTI chief's orders rather than fulfilling his constitutional duties. "Through his conduct, he has belittled the august Office by acting as a worker of the PTI, one who is beholden to Imran Niazi more than the Constitution & demands of his Office," he added, Geo News reported. The bill was approved by both houses of parliament last month and sent to the president for assent amid a deepening political and constitutional crisis in the country over elections in Punjab and Khyber Pakhtunkhwa provinces. After Alvi's refusal to assent to the legislation, the government is likely to get through this bill from a joint session of the parliament, Geo News reported. /IANS