Amit Shah has been involved in a cadre building exercise in Bengal, which has seen the BJP perform well

Highlights BJP beats Left to take second spot in Bengal by-poll

Ravi Shankar Prasad, Rajnath Singh, Uma Bharti now visit Bengal

Trinamool shrugs off BJP win, say it comes at the cost of Left

The BJP won five out of 10 seats in the by-election results announced yesterday, but is also pleased about a number 2 position in West Bengal's Kanthi Dakshin assembly seat. Party chief Amit Shah had "special thanks" for voters for making the BJP "the principal opposition party" in the state.Top BJP leaders have been assigned to travel to districts across Bengal to interact with party workers as the BJP prepares for panchayat elections in the state next year. Yesterday, Union Law Minister Ravi Shankar Prasad was in Hooghly. Today, Rajnath Singh and Uma Bharati are in Kolkata and Howrah.Chief Minister Mamata Banerjee's Trinamool Congress retained Kanthi Dakshin convincingly, leaving its rivals trailing far behind. But for the Left, stranded at a very poor third, the BJP emerging as the principle challenger to the ruling party is a big worry in a state it ruled for three decades before being ousted by Ms Banerjee in 2011. There was a margin of at least 30,000 votes between the BJP and the Left.A triumphant Trinamool Congress dismissed the BJP's growth saying it is all at the cost of the Left. "We are here to come first and between the first and second the difference is so huge that it does not matter who is second and who is third," said the ruling party's Mukul Roy. Former health minister Chandrima Bhattacharya of the Trinamool Congress won by a margin of almost 50,000 votes.The BJP's strong performance in a Trinamool bastion is being credited to its Ram Navami mobilisation. The BJP and the RSS have been working to expand its footprint in districts like East Midnapore where Kanthi is.The BJP had virtually no presence in West Bengal till a few years ago, but before the national elections of 2014 Amit Shah began a cadre building exercise that saw the party make its first impact that year. The BJP won two Lok Sabha seats and increased its vote share from four to 17 per cent.

In last year's assembly elections in West Bengal, the BJP won four seats, the party's best performance ever in the state.The Kanthi Dakshin seat fell vacant last year when Dibyendu Adhikari of the Trinamool Congress was elected to the Lok Sabha from Tamluk.