The sudden decision by Rajya Sabha member Shahid Siddiqui to join the Bahujan Samaj Party has brought jitters in the United Progressive Alliance camp, which is pinning its hopes on every parliamentarian possible to win the trust vote.

Special: An Alliance in Crisis

While the Congress is relying very heavily on the Samajwadi Party to cruise through the trust vote on July 22, several leaders in New Delhi feel that five more MPs from the party are expected to go against the government.

Siddiqui, who was the face of the SP in New Delhi till Friday evening, has the clout to influence at least five more SP MPs, according to sources both in the SP and the BSP.

2 days ago Shahid Siddiqui sang a different tune!

While, Siddiqi himself doesn't have a vote, his ability to pull five of SP's Lok Sabha MPs is seen as a critical blow to UPA's plans of touching the magic number.

When Siddiqui was questioned about this, he said he had not come out of the SP in order to defeat the Congress.

"I have certain thoughts about the deal and I started to realize that the BSP is the only party, which had addressed the problem of the Muslims. There are some members in the SP who share my view, but I have not coaxed anyone to come out of the party.

UPA still short of majority

"I do not know how many people will follow me. I also am not here to lobby. But Whoever calls me, I tell them why I am opposed to the deal and urge them to think well on how this deal will affect the nation before they vote," he said.

When asked specifically whether five more MPs from the SP would join him, he said, "I am not sure. There may be a possibility but I am not sure about it."

If that is the case, the Congress move of ditching the Left and roping in the SP is sure to backfire. While the SP has 39 MPs, the party has found it difficult to keep its flock together. From day one, some MP or the other has spoken against the deal and expressed their opposition to it openly.

'No amount of money can change my stand'

Four SP rebels have already decided to vote against the government. If five more MPs come out of the party, as sources suggest, then the strength of the SP in Parliament comes down to 30.

This will mean the Congress has to rope in fresh support to fill that void or depend on friendly MPs to abstain from voting.