Mohansinh Rathva, a 10-time Congress MLA in Gujarat, has quit the party less than a month to go for the assembly election in Prime Minister Narendra Modi's home state, where the Congress has been struggling to come to power for over two decades.
Mr Rathva, 78, joined the BJP this evening.
The MLA, which represents the Chhota Udaipur (Scheduled Tribes, or ST) constituency, has sent his resignation letter to Gujarat Congress boss Jagdish Thakor.
Mr Rathva is popular with tribals in his stronghold. Before 2012, he represented Pavi-Jetpur (ST) constituency in Chhota Udaipur district.
He recently announced he would not contest the Gujarat election this time, but wants to see his son, Rajendrasinh Rathva, fight from his seat.
On whether the BJP would give his son a ticket to contest the election, the MLA said he is "100 per cent" sure.
"However, I have not sought a ticket. I am getting old now. My son Rajendrasinh is an engineer. He is BE (Bachelor of Engineering) civil. He was having a feeling that we should join BJP," Mr Rathva told reporters at the BJP headquarters, news agency PTI reported.
Mr Rathva denied he left the Congress because the party did not give a ticket to his son.
"The Congress never said they will not give me a ticket (for my son). I decided before Congress said anything about it. I was impressed by the work done by the BJP government and PM Narendra Modi in our tribal areas. That is the reason why I have decided to join BJP," he added.
Congress MP Naran Rathva has also sought a ticket for his son from the same seat, PTI reported.
Gujarat will vote in two phases on December 1 and 5; counting is on December 8.
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