Imphal, Aug 20 : The crucial Manipur assembly session will not be held from Monday as the Governor Anusuiya Uikey did not formally summon the session, a top official said on Sunday. The previous assembly session was held in March. As per the norms, at least one assembly session must be held every six months. 'The state cabinet has recommended to the Governor for summoning the 4th session of the 12th Manipur Legislative Assembly on August 21,' an official release had said earlier this month. The reason behind not holding the assembly session from Monday was not given by any official. Political circles said that it is obvious that the ongoing ethnic violence and related issues would have to be discussed in the session, if it was held. The Congress legislature party led by former chief minister Okram Ibobi Singh on July 26 met the Governor and demanded to convene a special session of the Assembly under Article 174 (1) of the Constitution. The Congress leaders, who are demanding imposition of President's rule in Manipur, have been saying that the state Assembly is the most appropriate forum to discuss and debate the ongoing turmoil for which suggestions of measures to restore normalcy can be moved and discussed. Ten tribal MLAs, including seven ruling BJP MLAs, along with many other tribal organisations, since May 12 have been demanding for a separate administration for the tribals. The tribal legislators also said that they would not be able to attend the assembly session in Imphal due to 'security reasons'. Okram Ibobi Singh, a three-term former Chief Minister (2001-2017), on Sunday said that there would be a constitutional crisis in Manipur if the assembly session would not be held in six months. 'It is unprecedented that despite Cabinet request, the Governor did not convened the assembly session,' Singh, Congress legislature party leader, said while addressing a function on Sadbhavana Diwas, held on Sunday at the Congress Bhawan in Imphal to mark the 79th birth anniversary of former Prime Minister Rajiv Gandhi. Over 160 people have been killed and more than 600 injured since ethnic violence broke out in the state on May 3, when a 'Tribal Solidarity March' was organised in the hill districts to protest against the Meitei community's demand for Scheduled Tribe (ST) status. In view of the ethnic strife in Manipur, approximately 70,000 men, women and children belonging to different communities have been displaced and are now sheltered in 350 camps set up in schools, government buildings and auditoriums in Manipur and several thousand sought refuge in the neighbouring states including Mizoram. /IANS