The decision by SP, with 21 members in Lok Sabha, and RJD with four will, however, have no impact on the stability of the UPA government. The SP and the RJD were outside supporters of the government.
Angry SP President Mulayam Singh Yadav and RJD chief Lalu Prasad slammed the Congress for its move to "unilaterally" go ahead with the Bill which seeks 33 per cent reservation for women in Lok Sabha and state assemblies.
"This is a political dacoity. We will not tolerate it. We are withdrawing support to the government," said Prasad with Yadav standing by his side and supporting him.
He later said, "We have withdrawn support on this issue".
He, however, was evasive when asked whether a letter withdrawing support to the government had been given to the President.
Even if both SP and RJD formally withdraw support by giving letters to the President, the effective strength of UPA and its outside supporters would be around 290, well beyond the 272 mark for a simple majority.
Together the UPA parties -- Congress (208), Trinamool Congress (19), DMK (18), NCP (9), National Conference (3) and Muslim League (2) -- have a strength of 259.
However, with outside supporters like BSP (21), Jharkhand Vikas Morcha (1) and JDS (3) its strength goes upto 284 in Lok Sabha. It also enjoys support of some independents in the Lower House taking the total strength to around 290. The Lok Sabha has a strength of 543.
Mulayam Singh Yadav said that both Congress and the BJP have been against Muslim, backward and dalit women and don't want to give reservation to them.
"They do not want women from these sections to come forward...This has been proved now. They want to perpetuate their rule..." Yadav said.
Prasad said that from the beginning SP, BSP, RJD and Sharad Yadav have made it clear that they are not anti-women and against reservation to them.
"We want reservation also for the women who work in fields, work under the NREGA scheme, backward, dalits and the Muslims," Lalu said. "By not giving them reservation you are neglecting a large section of women in rural India," he added.
Senior RJD leader P C Gupta said that the party would formally send the letter of withdrawal of support to the President if the Bill was passed in the present form.
Prasad said, "The bill is against Dalits and Muslims and this will not be tolerated.We will exercise our democratic rights and oppose it."
Terming the Congress and BJP as anti-women, Lalu asked how many women were given tickets in Congress and BJP. "Both the parties are against Dalits and Muslims."
On Nitish Kumar supporting the Bill, Prasad said earlier Nitish was supporting the quota within quota proposal but now he has turned against it. "Anyway it was JD(U)'s party affair".
Lalu also condemned the Left for supporting the Bill. "What the Left doing now is not a right thing," he said.
When told that the government has numerical strength to pass the Bill, Lalu said we will exercise our democratic right to oppose it."
Both Lalu and Mulayam maintained that they are ready to face any consequences for opposing the Bill."We are ready to lose whatever... even our membership in the House but we will oppose the Bill as it is against social justice," they said.