Mamata Banerjee on Saturday said the BJP would not be invincible if Opposition parties engage in an "all-out fight" in all states across the country.

"I will fight all out against BJP and ensure victory (in the Lok Sabha polls). Kheltey hobey (we have to perform in the game), jeettey hobey (we will have to win). If political parties — both regional and national and frontal organisations — in all the states across the country fight the BJP in the same spirit (like ours), the BJP can be defeated," Mamata said while wrapping up her 48-hour sit-in demonstration against the Narendra Modi government's alleged deprivation of Bengal.

Trinamul's frontal organisations will continue with the sit-in.

"If the BJP thinks they are invincible, I'd like to remind them that no one stays in power forever," Mamata added.

Mamata's clarion call for all parties to put up an "all-out fight" came on a day activist Yogendra Yadav, who took part in her sit-in, urged her to lead the Opposition bloc by bringing all the non-BJP parties under one platform.

"Amar apotti nei (I don't have any objection)," Mamata said before rolling out her expectations from other parties and organisations.

The request from Yadav, lately seen with Congress leader Rahul Gandhi, assumed significance in the wake of Mamata's missive to the Congress that while she is committed to INDIA, there would be no alliance between Trinamul and the Grand Old Party in Bengal.

Over the last few days, Mamata communicated that Trinamul would take on the BJP alone in all the 42 seats in Bengal. The Left and the Congress in Bengal have begun seat-sharing talks.

Talks between the Left and the Congress for an alliance bode well for Bengal's ruling party as their coming together would split anti-Trinamul votes, a Trinamul source said.

"Didi doesn't want to join hands with the Congress.... Just remember what she said yesterday," said a Trinamul source referring to Mamata's comments on Friday when she expressed her doubts on whether the Congress would get "40 seats" in the country.

All was not well between the Congress and Trinamul in recent months. But the ties received a fresh jolt after Rahul Gandhi's Bharat Jodo Nyay Yatra entered Bengal without "informing" Mamata.

"What prevented him (Rahul) from writing to her directly or calling her up on the Yatra?" asked a source close to Mamata. "This is political immaturity.... The Congress could have handled the Yatra in Bengal differently."

The Congress central leadership, unlike its Bengal unit, was restrained during the Bengal leg of the Yatra despite facing non-cooperation from the administration or regular jibes at Rahul by Mamata and other Trinamul leaders. Jairam Ramesh, Congress's communications chief, showed restraint when asked on Friday about Mamata's doubts over the ability of his party to win seats. "We are assuming that she (Mamata Banerjee) is still part of the INDIA bloc, a group of 27 parties. Her priority, she claims, is to fight the BJP. Our priority is also to fight the BJP. I think it is better if we all come together," Ramesh told PTI.