Cornered by the Central Bureau of Investigation and the Supreme Court, which questioned his nationality, controversial Congress MP Mani Kumar Subba remains defiant even as his party is slowly distancing itself from him.

Subba, who is at Naoboicha, his brother's Assembly constituency attending a farmer's rally, on Friday averred that he was an Indian and the CBI was wrong.

But the Congress, sensing danger in associating with him, has started cold shouldering him even though he has been the party's main 'money bag' for decades.

"I am 101 per cent Indian. I am going to prove this and come out clean on the issue," the Lok Sabha MP from Assam's Tezpur parliamentary constituency said.

The CBI had informed the Supreme Court that the MP's birth certificates were not genuine and that he is a Nepali citizen. The CBI had conducted the inquiry following a direction by the court.

An apex court bench comprising Chief Justice K G Balakrishnan and judges R V Raveendran and M K Sharma had asked Subba to respond once the court reopens after the summer vacation, about six weeks from now.

"The court did not say anything in the order and only asked me to respond and I shall do the same accordingly," Subba said.

Subba's own declarations about his date of birth have varied from 1951 to 1958 and in his 13th Lok Sabha affidavit, he said he was born in Tezpur and not Siliguri.

If arrested, he might cause embarrassment for the Congress. But for now, the party is rallying in support, so much so that national spokesperson Abhishek Manu Singhvi is fighting his legal case.

However, the Congress is split on the issue. Majority of partymen want to dump him, while Chief Minister Tarun Gogoi played safe.

"He has been given six weeks time and the matter is sub-judice. We will act, if necessary, only after the Supreme Court verdict," Gogoi said.

Lottery baron Subba has been the main fund raiser for the Congress, a fact which helped him defy all opposition to get party tickets.

Assam government spokesman Ripun Bora as well as Congress MLA Bhupen Bora have been openly demanding his resignation.

"I shall complain to the party High Command about this. This is a complete defiance of party rules and regulations," Mr Subba, however, maintained.

The Congress in Assam officially has adopted a 'wait and watch' policy but nobody wants to share a dais with him.