Chairman of the Sadbhavana Party Rajendra Mahato has warned of the agitation if the constitution amendment proposal was not registered at the Legislature-Parliament before the Chhath festival. At a press conference organized at Jaleshwor, district headquarters of Mahottari on Monday, Chairman Mahato said if the Prime Minister does not become serious on constitution amendment, the agreement made with Madhesi parties would be breached and the support to government withdrawn.