Delhi Chief Minister Arvind Kejriwal and his West Bengal counterpart Mamata Banerjee during a dinner in New Delhi on Tuesday. (PTI photo)

West Bengal Chief Minister Mamata Banerjee is the driving force behind a tea party today that brings together political parties determined to ensure a defeat for the BJP in Bihar, where assembly elections are due in the next two months.The meeting will be held at the Delhi home of Nationalist Congress Party or NCP chief Sharad Pawar and the Samjawadi Party's Mulayam Singh Yadav will attend. Nitish Kumar and Lalu Yadav, the two Bihar heavyweights who have buried years of rivalry to take on the BJP in the state, will send representatives.Even Delhi chief minister Arvind Kejriwal will attend; he was persuaded by Ms Banerjee over dinner this evening, said sources.But, the Congress which is contesting the Bihar elections as a partner of Nitish Kumar's Janata Dal United and Lalu's RJD, has not been invited.Mamata Banerjee, said sources, insisted that the Congress, who she will be battling soon in assembly elections in West Bengal, must not be a part of today's strategy meeting.Ms Banerjee's Trinamool Congress does not contest seats in Bihar and her initiative to organise the "chai pe charcha" is seen as designed to signal to the substantial chunk of minority voters in her state, that she is firmly aligned against the BJP.The BJP, a minor player in Bengal so far, is beefing up its cadres in the state hoping to make big inroads in the next assembly elections. But before that it hopes to win neighbouring Bihar.While Mulayam Singh Yadav heads a group of socialist parties of which both the JDU and the RJD are a part, host Mr Pawar's NCP is a marginal player in Bihar and part of the Nitish Kumar-led coalition.Arvind Kejriwal of the Aam Aadmi Party has said he will not to field candidates in the Bihar elections to ensure anti-BJP votes are not split.Mamata Banerjee is in Delhi to meet PM Modi to discuss flood relief in her state.