Baba Siddique, a former Maharashtra minister and member of the Ajit Pawar faction of the NCP, has been shot at in Mumbai's Bandra and rushed to a hospital, where his condition is said to be critical.
Sources said three bullets were fired at Mr Siddique on Saturday evening at the office of his son Zeeshan, who is the MLA from Bandra East. He is undergoing treatment at the Lilavati Hospital.
Mr Siddique, who was a three-time MLA from Bandra West, was associated with the Congress for 48 years and had quit the party in February and joined Ajit Pawar's NCP. Zeeshan Siddique was expelled from the Congress in August.
The firing comes months ahead of the Maharashtra Assembly elections, which are expected to be held later this year.