The EFF has announced that it will not co-govern with any party, and has decided to support oppositi.
The 62-year-old was attacked by his 15-year-old son on Tuesday at his home in Palghar town, about 120 kilometres (75 miles) north of Mumbai, senior police inspector A.J. Sindkar told the Press Trust of India news agency.
The boy was angered that his father -- who has been divorced three times and widowed once -- planned to tie the knot again soon, threatening the youngster's inheritance prospects, police said.
The boy, who cannot be named for legal reasons, is being held on remand after being charged with murder.