TMC national general secretary Abhishek Banerjee travelled to Delhi on Saturday as the party leadership grappled with growing indications that the rebellion which cost it control of its legislature wing in the Bengal Assembly could spread to Parliament.

The visit, which came a day before Mamata Banerjee's scheduled trip to the national capital for the INDIA bloc meeting, has triggered speculation within party circles amid reports of efforts to engineer a split in the TMC's parliamentary ranks.

According to the original schedule, Mamata Banerjee and Abhishek were expected to travel to Delhi together on Sunday for the opposition INDIA bloc's meeting.

While the official reason for advancing the visit remains unclear, the development has triggered intense political chatter, with leaders and observers viewing it as a possible attempt by the TMC leadership to take stock of the situation before Monday's meeting.

Sources in the TMC said the party supremo herself asked her nephew to leave a day early. Party leaders, however, appeared uncertain about his engagements in Delhi on Sunday.

"I don't know why Abhishek is going to Delhi today. I am not in Delhi or Kolkata now. I haven't heard about any meeting," a TMC MP, who did not wish to be named, said when asked about the visit.

The uncertainty surrounding the trip has coincided with growing reports of efforts by dissident TMC leaders and MPs to replicate in Parliament what has already happened in the Assembly.

Only a few days ago, more than two-thirds of TMC MLAs, 58 of the 80 legislators, broke away from the party's official legislature wing and secured recognition as the principal opposition bloc under expelled MLA Ritabrata Banerjee, dealing one of the biggest organisational setbacks to Mamata Banerjee since she founded the party in 1998.

The rebellion, directed largely against Abhishek's growing influence in the organisation, was informally christened "Operation Crown Prince" by dissident leaders.

Now, political circles in both Kolkata and Delhi are abuzz with talk of another possible operation aimed at triggering a similar rupture within the party's parliamentary ranks.

"I think a similar development is happening in New Delhi in the parliamentary party. This is happening because of the high-handedness of Abhishek Banerjee," Rebel TMC MLA and deputy leader of the party's new legislative wing Sandipan Saha said.

The TMC currently has 28 members in the Lok Sabha after the death of Basirhat MP Haji Nurul Islam.

Under anti-defection provisions, a group would require the support of at least two-thirds of the parliamentary party -- 19 MPs -- to stake claim to a separate formation without attracting disqualification. The party has 13 MPs in the Rajya Sabha.

Sources familiar with the developments claimed efforts were underway to mobilise support among MPs in both Houses of Parliament.

Several party leaders said telephonic outreach to MPs intensified from Friday night and continued through Saturday, adding to speculation that rival camps were engaged in a contest for numbers.

A senior TMC leader acknowledged that concerns within the party could not be dismissed outright.

"The Assembly developments have naturally created apprehensions. Everyone is now keeping a watch on developments in Delhi," he said.

At the same time, leaders close to Mamata Banerjee maintained that reports of an imminent split were exaggerated and argued that many MPs remained firmly with the party leadership.

The possibility of unrest in Parliament was first flagged publicly by veteran Rajya Sabha MP Sukhendu Sekhar Roy.

"I have never seen around 60 MLAs leave in such a short span of time. A similar reaction is likely in the Lok Sabha too," Roy had said recently.

Asked whether such developments could extend to the Rajya Sabha, he had said the possibility could not be ruled out.

Senior TMC MP Sougata Roy, however, dismissed suggestions that the party was heading towards disintegration and accused the BJP of attempting to engineer a fresh political operation.

"The BJP may try an operation in the TMC's Lok Sabha and Rajya Sabha wings, similar to what happened in the Assembly. But Mamata Banerjee has fought bigger battles and will bounce back," he had said.

The timing of Abhishek's Delhi visit has also drawn attention because he has been summoned by the CID on Monday in connection with the alleged TMC MLAs' signature-forgery controversy.

The TMC leader had sought additional time, citing health reasons, but the request was rejected by the agency.

Whether Abhishek's early arrival in Delhi is linked to efforts at political firefighting, preparations for the INDIA bloc meeting, or a combination of both remains unclear.

For the TMC leadership, however, the stakes are considerably higher now than they were a week ago.

Having already lost control of its legislature party in the Assembly, the party is facing the prospect of a fresh battle to preserve unity in the Parliamentary team -- a contest that could determine whether the rebellion remains confined to Bengal or acquires a national dimension.