Campaigning in Mumbai amid the hot and humid weather, with temperature reaching 38 degree Celsius, PM Modi said Shiv Sena founder Balasaheb Thackeray believed that the day the Maharashtra party starts to follow the path of the Congress, it would be the end of the Shiv Sena.
"Maharashtra has made up its mind to punish the duplicate Shiv Sena, which has kneeled before the Congress," PM Modi said.
The Shiv Sena shattered into two factions after Sena leader and the current Chief Minister Eknath Shinde revolted against the then alliance government with the Congress and the Nationalist Congress Party (NCP).
Mr Shinde managed to keep the name of the party started by Uddhav Thackeray's father, and formed government in a partnership with the BJP.
"Smaller parties will merge with the Congress after the elections," PM Modi said. "Modi is the chowkidar of rights of oppressed people. He won't let them be snatched away... Splitting Budget on religious lines is dangerous, but for the Congress, minority means its dear vote bank," the Prime Minister said.
PM Modi had defended himself against Opposition criticism that he is stoking divisions between Hindus and Muslims to win the national elections as he filed his nomination on Tuesday for re-election from Uttar Pradesh's Varanasi.
"I believe people of my country will vote for me," PM Modi told CNN-News18 in Varanasi. "The day I start talking about Hindu-Muslim (in politics) will be the day I lose my ability to lead a public life," PM Modi. "I will not do Hindu-Muslim. That is my resolve," he added.