West Bengal Chief Minister Mamata Banerjee on Thursday regretted that Netaji Subhash Chandra Bose's birth anniversary was yet to be declared as a national holiday, as she criticised the BJP-led NDA government for not being "serious" in solving the mystery behind his disappearance.

She also recalled the revolutionary leader's opposition to the "divisive politics" of the Hindu Mahasabha.

Addressing a function celebrating the 123rd birth anniversary of Bose, Banerjee recalled his speech at a public meeting on May 12, 1940, where he had strongly criticised the Hindu Mahasabha.

"Netaji had opposed the Hindu Mahasabha's divisive politics. These thoughts are very much relevant today. He had fought for a secular India, a united India, but now efforts are on to oust those who follow secularism," Banerjee said during a programme organised at the Darjeeling Mall.

Refering to the mysterious disappearance of Bose since August 18, 1945, Banerjee said the Modi government only declassified a few files, but did not take any measure to find out what actually happened to Bose.

"I find they are not serious in finding out what happened to him. It is a shame that after over 70 years, we still don't know what happened to him," she said.

Banerjee said since coming to power in 2011, she has been demanding that January 23 be declared a national holiday. "But this has not happened yet.".

"We will continue to follow the path shown by him. None can snatch his place from our heart."