Patna, April 4: RJD chief Lalu Prasad has appealed to all non-BJP political parties to come together on a platform to counter the "aggressive" Hinduvta agenda of the BJP led by Prime Minister Narendra Modi, in view of the 2019 Lok Sabha elections.Sensing a tough challenge, Lalu Prasad has also warned that a united non-Bharatiya Janata Party political force will be the only option to take on the BJP and Modi in the next general elections.Lalu Prasad's major ally Bihar Chief Minister Nitish Kumar has already said a "Mahagathbandhan" (Grand Alliance) of non-BJP parties is needed at the national level to defeat the BJP in the 2019 Lok Sabha polls."I have appealed to all non-BJP parties to come together on a platform. Unity among non-BJP parties is the only option available now to defeat the BJP in the 2019 Lok Sabha polls," Lalu told media here on Tuesday.Lalu Prasad said if non-BJP parties remain divided and fail to unite as a political force, they will be finished."I have already initiated talk with several top leaders of different regional parties with commitment to social justice agenda for unity among the non-BJP parties across the country," he said.The Rashtriya Janata Dal chief said that initially he has started approaching different leaders on the telephone, and this will be followed by his personal visit to talk to them face to face. After that, all like-minded leaders of different parties will sit together to formulate something concrete, he added."We have to come together soon to chalk out strategies because after one year, there will be little time with us to prepare for the 2019 polls."Lalu said Mamata Banerjee's Trinamool Congress is a strong force in West Bengal, AIADMK and DMK are strong forces in Tamil Nadu, while the Biju Janata Dal is strong in Odisha, Mayawati's Bahujan Samaj Party and Samajwadi Party of Akhilesh Yadav are strong in Uttar Pradesh. "If BSP, SP and Congress had joined hands like the JD-U, RJD and Congress joined hands in Bihar, the result of the Uttar Pradesh polls would have been totally different. The BJP got an opportunity due to a clear cut split in opposition votes."Lalu Prasad cautioned that Modi may go for early Lok Sabha polls to cash in on the massive victory in Uttar Pradesh assembly polls. "I and my party RJD are ready for it, but others have to be ready to face any such situation," he said.Lalu Prasad said the Congress is a national party and it should come forward to unite non-BJP parties.Nitish Kumar, who is also president of the Janata Dal-United said that a "Mahagathbandhan" would prove successful in the next parliamentary polls.