Veteran CPM leader Nirupam Sen, who had spearheaded West Bengal's industrial drive, died at a Calcutta hospital on Monday morning after prolonged illness, family sources said.

He was 72. The former Politburo member left behind his wife, a son and a daughter. Sen passed away at 5.10 am following cardiac arrest, hospital sources said. The former West Bengal commerce and industry minister was on life support system after his health condition deteriorated in early December and had been critical since then. 'Sen was fighting kidney ailments. He was impaired by a cerebral attack in 2013,' an official at the hospital said.

It was during Sen's tenure as state industry minister that the Singur controversy had broken out over the Tata Nano project.

One of the most prominent faces of the Buddhadeb Bhattacharjee cabinet after the CPM-led Left Front was voted to power in 2001, Sen was handed the charge of commerce and industries. It was under the leadership of Bhattacharjee and Sen that the Left Front started selling the dream of industrialisation in the state and shifted focus to private investments.

This shift in the policy reaped them heavy dividends, resulting in the Left Front's resounding victory in the 2006 Assembly election.

The Buddhadeb Bhattacharjee government acquired 997 acres of farmland at Singur in Hooghly district and handed it over to the Tata Motors in 2006 to set up the manufacturing plant of its Rs 1 lakh-car, Nano.

But by the end of 2006, protests against the land acquisition at Singur for the Nano plant had started taking a toll on the regime. The protests ultimately led Tata Motors to shift the car plant from Singur to Gujarat in 2008.

Led by the then Opposition Trinamul Congress, the anti-land acquisition protest in Singur and Nandigram was one of the reasons behind the fall of the 34-year-old Left Front government in the state in 2011.

Faced with intense criticism both within and outside the party, Sen, then a CPM Politburo member, had withdrawn himself from active politics.

In the next few years due to ill health, he stepped down from the Politburo, the central committee and earlier this year during the CPM party congress, he stepped down from the state committee.

Sen was a three-time MLA from Bardhaman Dakshin constituency.

Party sources said Sen's body would be taken to his residence and then to a private mortuary in the city. 'On Wednesday, Sen's body will be taken to the CITU office here and then to the party's state headquarters, where people will be allowed to pay their last respects,' a source said.

His mortal remains will be consigned to flames in Burdwan, his hometown, on Wednesday.

Bengal chief minister Mamata Banerjee and CPM general secretary Sitaram Yechury condoled the death of the Marxist leader.

'Saddened at the passing away of Nirupam Sen, former Minister of West Bengal. Condolences to his family and well wishers,' Mamata Banerjee said in a tweet.

In his condolence message, Yechury described Sen as 'a dedicated Communist, who devoted his entire life to the cause of the working class and the peasantry'

The party's West Bengal secretary, Surya Kanta Mishra, Politburo member Md Salim and other leaders also offered their condolences.