When P Chidambaram was asked if Mamata Banerjee had discussed bringing forward the Assembly polls in Bengal, he had avoided a direct answer. But not Finance Minister Pranab Mukherjee."It’s a Constitutional provision; it's not a party matter. Trinamool Congress has demanded earlier polls because the ruling party has lost successive elections. That's the rationality of demanding. But it is basically a Constitutional problem. The Election Commission has to decide," Pranab said.