Questioning BJP's claim of a wave in favour of its prime ministerial candidate Narendra Modi, Digvijaya Singh on accused the party of engineering defections.
The Congress leader also alluded to the internal rift within the main opposition party in the backdrop of senior leaders being denied the choice of tickets.
"In a Modi wave why is BJP engineering defections and giving seats to defectors? What happens to BJP loyalists?," Singh tweeted.
BJP has denied a ticket to senior leader Jaswant Singh and instead decided to field recent entrant Col Sonaram Choudhary in Barmer, which Singh was seeking.
The denial of ticket to Singh, who is considered close to LK Advani, comes after the party patriarch was virtually forced to choose the Gandhinagar seat in Gujarat, against his wishes to contest from Bhopal in Madhya Pradesh.
There is speculation that Singh might contest as an independent but there was no confirmation. Choudhary had recently defected from the Congress.
Launching a scathing attack on Narendra Modi, he questioned whether the BJP's Prime Ministerial candidate was bigger than the party and RSS.
"Modi bigger than BJP and RSS?," Singh wrote on the micro-blogging website.
Congress had earlier said that the party's Prime Ministerial nominee was the "epicentre" of all troubles within the saffron outfit.