In West Bengal, Chief Minister Mamata Banerjee today greeted the former Prime Minister Atal Bihari Vajpayee on his 91st birthday. The CM wising the former PM in a tweet said, "Respectful birthday wishes to Atal Ji. The Pradesh BJP and its units in Kolkata organized welfare-oriented events to mark the day. <br/><br/>The celebrations came amid reports that the party's newly-appointed Bengal president Dilip Ghosh has received a green signal to change most of the 20 district chiefs of the BJP in Bengal. Ghosh has been given a go-ahead to freely reshuffle the party units in the state to enable the BJP to fight Trinamool Congress government effectively. The changes will be announced within a day or two.<br/><br/>In a prelude to the coming Assembly elections, BJP will organise four Rathyatras in West Bengal from 20th to 31st January next. Party chief Amit Shah and other national leaders are likely to attend the flagging-off ceremonies of these Raths at Medinipur, Purulia, Sagar Island and Kochbehar on the 20th, party sources informed AIR today. These Rathyatras will tour all the 294 assembly segments of the State.