Stung by the failure of the central government to get the Bill on SC/ST quota in promotions passed in the Lok Sabha, BSP chief Mayawati put the Congress on a virtual notice. Mayawati said she always doubted the Centre's sincerity on the issue. 

"We will write to the PM for a special session. We will give them one or two more chances. We will raise the issue again in the Budget Session", the miffed BSP chief said.