Shashi Tharoor, who was sacked as Congress party spokesman in the wake of his effusive praise of Prime Minister Narendra Modi’s Swachh Bharat programme, on Thursday attacked the Union government for "ignoring the martyrdom" of Indira Gandhi, whose death anniversary falls on Friday.

“Disgraceful that govt is ignoring the martyrdom of our only prime minister who was killed in office in the line of duty. Oct 31 forgotten?” Tharoor said on micro blogging site Twitter.

Coverage: Indira Gandhi assassination anniversary

The Modi government has declared October 31 as Rashtriya Ekta Diwas (National Unity Day) to mark the birth anniversary of the country's first home minister Sardar Vallabhbhai Patel.

There was no mention of Indira Gandhi in the government announcement although it is also the death anniversary of the former prime minister who was shot dead by her bodyguards in 1984.

The government has also decided that it will associate only with the birth and death anniversary of Mahatma Gandhi. The anniversaries of other departed leaders may be observed by respective trusts, parties, societies or supporters. It has also decided not to convert government bungalows into memorials.

Tharoor, party MP from Thiruvanathapuram, had come under severe attack from Kerala Congress leaders after he said he felt "honoured" to accept the PM’s invitation to join the Swachh Bharat Mission.