Senior BJP leaders including L K Advani and party president Nitin Gadkari are taking part in a crucial meeting of party's office bearers in Kolkata today in view of the upcoming assembly elections in five states. Party's central observer Chandan Mitra said that Arun Jaitley, Rajnath Singh and chief ministers of BJP-ruled states are also attending the meeting. Stating that all election-related matters will come up for discussion at the meeting, Mr. Mitra said, they are going to concentrate on some winnable seats in West Bengal. He said that BJP would explore possibilities of having electoral tie-ups with smaller parties in North Bengal.Kerala, Tamil Nadu, West Bengal, Assam and Puducherry are going to polls in May. Mr Mitra said, in West Bengal, BJP will contest all the 294 Assembly seats.