The Rajya Sabha will on Monday vote on the controversial Constitution (117th Amendment) Bill 2012 that seeks to provide reservation in government jobs for Scheduled Castes and Scheduled Tribes.

While the Bahujan Samaj Party (BSP) has been pressing the government to pass the bill, the Samajwadi Party (SP) has issued veiled threats saying it could reconsider its outside support to the ruling United Progressive Alliance (UPA) if the bill is passed.

SP chief Mulayam Singh Yadav had said in Lucknow on Saturday, "If voting is done on the bill in the house, I will reconsider my party's support to the government."

BJP vice-president Mukhtar Abbas Naqvi told reporters, "The SP and BSP are hand-in-glove with the Congress. On several occasions, the two have jumped in to save the UPA government. The threat by Mulayam Singh Yadav is mere political posturing."

Parliament has been disrupted frequestly over the issue since the winter session started November 22.