New Delhi:�An ex-serviceman allegedly committed suicide by consuming poison over the issue of One Rank One Pension scheme (OROP) here. The 70-year-old ex-serviceman Ram Kishan Grewal from Haryana's Bhiwani district ended his life in the lawns behind the Jawahar Bhavan, which houses the Ministry of External Affairs, last evening. Police said he along with three of his companions had come to the city apparently to submit a memorandum to the Defence Ministry over the issue of OROP. Defence Minister Manohar Parrikar said he was saddened over the death of Grewal. "Saddened by the death of subedar Ram Kishen Grewal. I express my heartfelt condolences. I have asked officials to provide me with details," Parrikar said in a tweet. According to his friends, Grewal, who served in the Army and the Defence Security Corps for 30 years, had been upset over the issue for sometime. Defence Ministry sources said as per records, no request for appointment with Parrikar was made. Chief Minister Arvind Kejriwal targeted Prime Minister Narendra Modi over the suicide of an ex-serviceman here, saying both farmers and soldiers were ending their lives in his regime. Kejriwal, a bitter critic of Modi, also alleged that the Prime Minister was "lying" that the One Rank One Pension (OROP) scheme was being implemented by the Centre, contending that ex-serviceman, Ram Kishan Grewal, would not have committed suicide if the scheme was being executed by the Centre. A group of ex-servicemen led by Major General Satbir Singh (Retd) have been protesting against the OROP scheme introduced by the government. He is now an advisor to a new political party, Fauji Janta Party, which will fight in the upcoming Punjab Assembly Polls. The alleged suicide came just days after a one-man judicial committee on OROP submitted its report to Parrikar. The Centre, which has implemented the OROP, a demand which had been pending for decades, had appointed the committee under the Chairmanship of Justice L Narasimha Reddy, retired Chief Justice of Patna High Court to look into the anomalies, if any, arising out of implementation of OROP. The Ministry is currently studying the report and sources had said it will take a decision soon. The ex-serviceman have been holding protests at Jantar Mantar, Delhi's designated site for protests, to demand changes in OROP. Protesters say four of their primary conditions have not been met by the government. The main demands are revision of pension every year rather than the five years as decided by the government and OROP being extended to pre-mature retirees. Rajya Sabha MP Rajeev Chandrasekhar said he is anguished by the suicide of Grewal of 105 Infantry Btn (TA) and DSC. "He died at Jantar Mantar where veterans have protested in the past and some continue to protest despite my calls to call off the protest. My deepest condolences to his family and his friends," he said in a statement. The MP urged Parrikar to urgently resolve the outstanding issues/anomalies of OROP and also the 7th Central Pay Commission that continue to agitate and worry those serving and the veterans. "I urge him, as I have done repeatedly, to involve direct representation from the armed forces in resolving these issues and not leave it only to the bureaucrats and to do so urgently," he said.