New Delhi, July 19 : The Samajwadi Party suffered a setback on Saturday when one of its general secretaries and Rajya Sabha MP Shahid Siddiqui quit the party to join the rival Bahujan Samaj Party.

"For the last one month, I have been feeling uneasy over the nuclear deal. I am of the opinion that it is not in the national interest. I have been opposing it for the last three years," he told reporters after a meeting with Uttar Pradesh Chief Minister Mayawati.

Mayawati was by his side when he made the statement.

Siddiqui, a journalist by profession, said that he was heeding his conscience and would oppose the deal to the hilt.

"I am the one who had held Bush''s hand and told him that India will not accept the deal," he said.

Though Siddiqui''s resignation does not affect Samajwadi Party''s numbers in the Lok Sabha, it comes as a huge embarrassment to the party that has been at the forefront of attempts to muster numbers for the UPA Government in the trust vote next Tuesday.

Siddiqui, who was with Congress before joining the Samajwadi Party, said he would work with Mayawati for the cause of Dalit-Muslim unity and for the welfare of people of all castes.

Siddiqui''s decision came after another Samajwadi MP, SP Singh Baghel, decided to vote against the UPA Government.

Baghel said: "The deal is anti-Muslim. The Samajwadi Party must realise that its vote bank has now shifted form Yadavs to the Muslims."

Other MPs of the Samajwadi Party who have decided to defy the party whip and vote against the UPA are -- Rajnarayan Budholiya of Hamirpur, Jai Prakash of Mohanlalganj constituency and Munawwar Hasan of Muzaffarnagar constituency. (ANI)