Bahujan Samaj Party chief Mayawati on Thursday threatened in the Rajya Sabha that her party may withdraw outside support to the Congress-led United Progressive Alliance government.

The decision comes two days after the Central Bureau of Investigation questioned the BSP leader in a disproportionate assets case.

She said if the CBI was working at the behest of the Centre in the case, then her party would be compelled to withdraw its support to the UPA.

The BSP has 18 members in the Lok Sabha.

Mayawati demanded that just as the CBI had questioned her in the DA case, the agency should question other party presidents as well.

The BSP leader said she was raising the issue not to save herself or to exert pressure on the Centre, but to apprise the members in the House of the 'double standards' being adopted by CBI.

"Is this because I am a dalit?" she asked and wondered why the CBI had given her a clean chit earlier.

Responding to her remarks, Minister of State for Personnel Suresh Pachauri said the CBI was an autonomous body and the DA and Taj Corridor cases referred by her were instituted during the National Democratic Alliance regime.

He added that the UPA government did not have any influence over them nor has it interfered with the cases, which are proceeding as per Supreme Court directive.