Senior Congress leader Pranab Mukherjee today said, his party will form an alliance with Trinamool Congress to fight the 2011 Assembly election in West Bengal. Brushing aside speculations of tension with ally Trinamool, he said, in the last Lok Sabha election the parties had fought together after forging an alliance and there will be an alliance in the Assembly polls too. Mr Mukherji was talking to reporters in Kolkata. On December 20, Trinamool Congress leader Partho Chattopadhyay threatened to go it alone in the Assembly election next year following former union minister PriyaranjanDas Munshi's wife Deepa's accusation that Mamata Banerjee was running a 'disrespectful' alliance. However, the the next day Banerjee clarified that she had not said her party would contest on its own, but it was for the ally to decide.