The Trinamool Congress -- expanding rapidly at the cost of the Congress -- on Sunday assured that it will remain a part of the united opposition, allaying concerns of a rift ahead of the coming winter session of parliament. But senior party leader Derek O' Brien made one thing clear -- that its equation with the Congress was not the same as other parties.
Maintaining that "common issues that will unite the opposition", Mr O'Brien, the Trinamool's Parliamentary Party leader in Rajya Sabha, said: "I also must point out that there is a distinction between the RJD, DMK, RJD and the CPM -- they are all electoral allies of the Congress. The NCP-Shiv Sena and JMM run a government with the Congress".
"The Congress is not our electoral ally nor are we running a government with them. That's the difference," he added.
The Trinamool, once an ally of the UPA, had walked out of the coalition in 2012 over diesel price hike and retail reform, reducing the government to a minority. Till 2014, the government had survived on outside support of the Samajwadi Party and Mayawati's Bahujan Samaj Party.
Over the last months, the Trinamool has been racing towards the political space occupied by the Congress, absorbing a number of disgruntled leaders of the party on the way.
Last week, it became the principal opposition party in Meghalaya as 12 Congress MLAs, led by Mukul Sangma, joined up.
On Sunday, it declared itself the main opposition in Tripura, saying it won a bigger vote share than the CPM, which ruled the state earlier.
Aided by election strategist Prashant Kishor, Trinamool chief Mamata Banerjee is laying elaborate groundwork for the 2023 polls in Goa and Tripura.
Over the last week, she also gained foothold in Haryana and neighbouring Bihar with induction of key leaders from the Congress and Nitish Kumar's Janata Dal United.
The Congress has maintained calm, barring an outburst or two from Adhir Chowdhury, its leader on the Lok Sabha, who called Ms Banerjee a "Trojan horse of the BJP".
The Congress's leader in Rajya Sabha, Mallikarjun Kharge quickly moved in for damage control, saying they were trying their best to work with Trinamool and rally the opposition.
"Whatever the outside political scenario, but inside we should be united to redress the grievances of the common people," Mr Kharge told NDTV.
It was Mamata Banerjee who ripped off the band aid last week, declaring that meetings with Sonia Gandhi every time she came to Delhi were "not mandatory".
Back in Bengal, Trinamool leaders were blunt.
"The Congress has done nothing to fight the BJP in the last seven years. It is the TMC that put up a battle against the BJP. We have never talked of stitching an opposition alliance without the Congress. But the Congress has to realise that its big brother attitude will no longer be accepted," Kunal Ghosh, the general secretary of Bengal's ruling camp, was quoted as saying by news agency Press Trust of India.