New Delhi, Aug. 31: The Congress high command had been alerted in time to the possibility of a split in the Bihar unit but what has rattled Sonia Gandhi is the alleged betrayal by the custodian who had been entrusted with the task of keeping the flock together.

Top sources in the party told The Telegraph that at least three Congress MLAs had written to Sonia over the past few days that state unit chief Ashok Chowdhary had "fraudulently" taken their signatures on a letter that suggested a split in the legislature party and pledged support to the Nitish Kumar government.

This triggered a desperate counter-operation by the central leadership to salvage the situation.

Before these letters to Congress president Sonia, an MLA had confided in Jyotiraditya Scindia, who had been sent to Bihar last week to assess the situation amidst rumours that Chowdhary was "coercing" leaders in the state to cross over to the Janata Dal United.

Although Chowdhary and legislature party leader Sadanand Singh firmly countered the claims, Scindia conveyed to Sonia that something was cooking in Bihar.

Both Singh and Chowdhary were summoned to Delhi today. They denied any "plot" at a meeting with Sonia where senior leaders Ahmed Patel, Ghulam Nabi Azad and the general secretary in charge of Bihar, C.P. Joshi, were also present.

Chowdhary told the media after the meeting: "The Bihar Congress unit is intact and we discussed a plan to strengthen the party."

Azad too denied any possibility of a split in the state unit.

Sources, however, said Chowdhary, who is a member of the Bihar Legislative Council, had already obtained the signatures of 14 MLAs and was working on a few more as the consent of 18 legislators is required for a formal split.

The Congress has 27 MLAs in Bihar and if two-thirds of that number defect, it will be recognised as a formal split that will not invite action under the anti-defection law.

When Azad went to Patna on August 27 for Lalu Prasad's rally, both the RJD chief and some Congress legislators explained to him the "entire conspiracy" to split the Congress in Bihar.

Chowdhary was said to be unwilling to be seen at the rally but Azad forced him to come on the dais to read out Rahul Gandhi's speech. Azad is too seasoned a player to misread the political signals and promptly launched a counter-operation, sources said.

Some MLAs who confessed to having signed the letters were immediately asked to get affidavits prepared saying their signatures were taken under duress. Similar affidavits are being made for the other MLAs too.

Chowdhary and Singh were called to Delhi for a face-to-face confrontation as the last chapter of the counter-offensive. The Congress now feels it has busted the alleged plot though some key players may still leave in embarrassment after being "caught red-handed".

A senior Congress leader said: "It is a classic case of the custodian looting the treasure. Chowdhary and Singh are PCC chief and CLP leader, respectively. We trusted them to serve the party's interest but they were working for the betrayer Nitish Kumar. We know Nitish Kumar was operating through his confidant Lallan Singh. The BJP-JDU government rests on a slender margin and Nitish wants to fortify his position through defections."

The leader said Singh, who has been a PCC chief and a minister in the past, might not have approached the ruling JDU himself, "but we have credible information that he had been instigating MLAs to defect".

A Kurmi by caste, Singh has excellent rapport with JDU chief Nitish.

Chowdhary had allegedly been using pressure, threats and allurements to win over MLAs. Some of them have informed the party in detail about his activities.

Both Singh and Chowdhary had "refused to criticise" Nitish after the chief minister broke ranks with the Opposition and returned to the NDA fold, although Sonia and Rahul had taken a tough line.

Sources said Chowdhary was in control of eight MLAs who are known to be his supporters. But he needed 18 and so was forced to step out of his comfort zone to lure other MLAs, the sources claimed. This apparently proved to be his undoing and the "plot" got leaked.

Congress leaders expressed outrage at Chowdhary's "betrayal" as Rahul had refused to replace him as Bihar party chief for the past two years despite "serious complaints" against him.

Almost the entire state unit was opposed to his continuance as Bihar Congress chief but general secretary Joshi continued to "protect" him.

Many senior leaders blamed Rahul's "obstinacy" for the developments, saying he had refused to listen to the majority opinion in the Bihar Congress. "This ugly episode gives credence to the charge that Rahul has often backed wrong people," a leader said.