Sugato, a Harvard University professor, is contesting from Jadavpur constituency where his family members have gone out to campaign against him and support CPI(M) candidate Sujan Chakraborty instead.
"Sugato has refused to support the demand for declassification of files relating to the mysterious disappearance of Netaji after which we decided to campaign against him as he has betrayed us and the Bose legacy," Netaji's another grand-nephew Chandra Bose said.
Along with other admirers of the freedom fighter, around 30 family members of Netaji have come together under the ‘Open Platform for Netaji'.
The forum members said Sugato had told them that declassification was a non-issue, but the PMO had admitted in an RTI reply that they had secret files with them.
"Netaji belongs to the nation and not only to one family. And we want that the truth about his life should be out in the open. Since Sugato is not supporting us in this initiative we have decided to oppose his candidature," Chandra Bose said.
All India Forward Bloc, one of the constituents of the Left Front, has even included the Netaji issue in its poll manifesto.
"Disappearance of Netaji Subhas Chandra Bose will be re-enquired on the basis of Mukherjee Commission report. All the files of INA and Azad Hind Government will be declassified," the manifesto says.
The family members had also earlier appealed to West Bengal Chief Minister Mamata Banerjee to demand declassification of files, but got no response.
"Now since Sugato is standing for elections, he has become a public figure and must clarify his stand on the issue," Bose said adding that they had also written to him seeking support.
Sugato Bose has refused to comment on the matter while denying the receipt of any such letter.
With their unmet demands, many Netaji scions are now campaigning for CPI(M) candidates in the hope that they will support the declassification issue.
Netaji's grand-daughter Madhuri Bose is campaigning for Barrackpore Lok Sabha constituency's Left Front candidate Subhashini Ali.