The Congress on Thursday hit back at Mamata Banerjee with full force, questioning her credentials to lead the fight against the BJP by recalling her past partnerships with the party that she had once described as Trinamul’s “natural ally”, the gloves coming off after her political strategist taunted Rahul Gandhi without naming him.

Prashant Kishor, widely believed to be the brain behind the project to take the Trinamul Congress footprint beyond Bengal, had tweeted earlier in the day: “The idea and space that the Congress represents is vital for a strong Opposition. But Congress’ leadership is not the divine right of an individual, especially when the party has lost more than 90% elections in last 10 years. Let Opposition leadership be decided democratically.”

The Congress had so far exercised restraint, not criticising the Trinamul’s foray into states where it is locked in a direct fight with the BJP or its wooing of Congress leaders, believing that Trinamul was perhaps acting under pressure.

Mamata’s observation on Wednesday that “you cannot fight fascist forces by remaining in foreign countries half the time” had angered the party’s middle-rung leaders and workers who demanded a sharp response to the “personal attack” and began speaking out. But it was Kishor’s tweet that yanked the covers off a “sinister game plan”, party leaders said.

The party’s communications chief, Randeep Surjewala, said: “Mamata Banerjee said on August 20 that all parties should come together to protect democracy. Democracy can’t be protected by directly or indirectly helping the BJP. You go to Goa and start attacking the Congress because the BJP is losing there. You go to Uttarakhand because the BJP is in trouble there as well.”

He continued: “The Congress is ready to take every party along but the regional players will have to decide their priorities — they have to fight the Congress or the BJP.”

Surjewala recalled that Mamata had twice been a minister in a BJP government. “There is a difference between a battle of principles and political opportunism. Mamataji joined the BJP-led NDA in 1999 and became the rail minister in the Vajpayee government. She quit the NDA in 2001 only to return in 2003 to become mining minister,” he said. “She said ‘BJP is our natural ally’.”

“She (Mamata) fought the 2004 general election along with the BJP and again turned against them in 2008. She joined the UPA and resigned in 2012. A leader whose career is marked by political opportunism and ideological compromises needs to introspect, not to give sermons to the party that remained opposed to the RSS philosophy whether in power or in Opposition,” Surjewala said.

“For the Congress, fighting the RSS ideology is an article of faith, not a matter of political expediency,” he stressed.

Drawing similarities between Mamata and Prime Minister Narendra Modi, he said: “Both buy MLAs, break other parties. The tactics are the same. Has the fascist thought become the source of inspiration for her?”

Surjewala refused to comment on Kishor, saying he would not respond to a “consultant, especially someone who was also Modi’s consultant”.

But another spokesperson, Pawan Khera, tweeted: “Hell hath no fury like a strategist scorned.”

There was speculation that Kishor had been in talks with the Congress to work towards a blueprint for the 2024 Lok Sabha elections, but nothing came of it.

Khera also said: “Rahul Gandhi is pursuing the divine duty of the Congress to struggle and save Indian democracy from the RSS. A professional without ideological commitment is free to advice parties/individuals on how to contest elections but he cannot set the agenda of our politics.”

Another party spokesperson, Gourav Vallabh, told The Telegraph: “Mamata’s political opportunism isn’t new, there is a history. She never showed ideological qualms in joining hands with the BJP while our fight is purely ideological.”

Asked about Kishor, Vallabh said: “Political battles are won on the basis of ideology, not tricks.”

Even party leaders who have been unhappy with the Congress leadership and who had been hailing Mamata till a few days ago disapproved of the tactic of attacking Rahul Gandhi through Kishor.

The AICC secretary in charge of Bengal, B.P. Singh, said: “Mamata Banerjee did for the BJP what Syama Prasad Mookerjee couldn’t. She turned a non-existent BJP into a big force in Bengal. She provided the platform by aligning with the BJP.

“She is committing a blunder by falling into the trap laid by Prashant Kishor. Her core supporters will desert her if she implements Kishor’s agenda of propping up the BJP. The perception has travelled to the masses that she is hurting Opposition unity and helping the BJP in the critical Assembly elections.”