Recovering from the stunning ambush on Wednesday, Congress appears set to wean away Mulayam Singh Yadav from his new-found alliance with Mamata Banerjee and is on its way to nominating Pranab Mukherjee for the President's post. In what could precipitate Mamata Banerjee's exit from the UPA, Congress has, encouraged by signs of Mulayam's rethink, decided to take on the Trinamool chief by sticking to the finance minister as its nominee for the July 19 presidential polls.