New Delhi, Sep 4 (IANS): Soon after the union cabinet Tuesday approved a constitutional amendment bill for reservation in job promotions to Scheduled Castes and Scheduled Tribes, the Samajwadi Party said it will not let the bill pass in parliament.

The party, which has taken a stand against the bill, accused the government of taking a politically motivated decision.

"We are against the bill. It is unconstitutional," Samajwadi Party (SP) leader Ram Gopal Yadav said.

"The Supreme Court has quashed it. Still the government wants to bring the bill because it is politically motivated," Yadav told reporters here.

"Just as we did not allow the women's reservation bill to be passed, we will not allow this bill either," Yadav told IANS.

But main opposition party BJP said that though it would support the bill, some of its members had reservations and would suggest amendments.

"We are supporting the bill. But some members have some reservations. We will discuss it and suggest some amendments," Bharatiya Janata Party (BJP) leader Mukhtar Abbas Naqvi told IANS.

Union Law Minister Salman Khurshid, however, said the government was committed to getting the bill passed.

"It was a decision taken in an all-party meeting. It is everyone's view," Khurshid said.

According to government sources, the bill is likely to be tabled in parliament Wednesday or Thursday.