Congress president Sonia Gandhi, in a letter to Sena Chief Uddhav Thackeray before his swearing in as Maharashtra CM on Thursday, wrote that the Shiv Sena, Nationalist Congress Party (NCP) and Congress have come together under extraordinary circumstances at a time the country faced "unprecedented threats" from the BJP. Her son Rahul Gandhi, who is also not attending the oath ceremony, wrote in a separate letter that he was "glad" the alliance had come together against the BJP and expressed confidence that it would provide a "stable, secular and pro-poor" government.

The political atmosphere has become poisonous and the economy has collapsed, Sonia Gandhi wrote. "Farmers are facing great distress. The Shiv Sena, NCP and the Congress have agreed to a common programme and I am confident that all three parties will strive their utmost to implement that programme in letter and spirit," she said in the letter.

The people of Maharashtra expect the alliance to provide cohesive, purposeful, responsible, responsive and transparent administration and our collective effort will undoubtedly be to ensure that these expectations are fulfilled," the Congress president wrote in her first ever letter to the Shiv Sena chief.

Sonia Gandhi said she would be unable to attend the oath ceremony, noting that Mr Thackeray's son Aaditya "met me yesterday and extended your kind invitation".

"I wish you personally all the very best as you embark on a new innings in your life," she wrote.

Aaditya Thackeray flew down to Delhi last evening and met several political leaders including Sonia Gandhi and former Prime Minister Manmohan Singh to invite them to his father's oath ceremony.

The BJP tried to corner the Congress on Thursday over the Shiv Sena praising Mahatma Gandhi's assassin Nathuram Godse in the past and wondered if this was why Rahul Gandhi was "ashamed" to attend the swearing-in ceremony of the Maharashtra government.

The Congress-NCP alliance in Maharashtra has joined hands with the Shiv Sena, a long-time Hindutva ally of the BJP before they split, and Sena chief Uddhav Thackeray was sworn-in as the chief minister on Thursday.

"Stop being a hypocrite Rahul Gandhi. You are making someone with identical views Chief Minister of Maharashtra. Udhav Thackeray, Editor-In-Chief of Saamana, wrote that Godse was a Patriot. Is that why you are ashamed to attend swearing-in," BJP spokesperson G V L Narasimha Rao said in a tweet.

Rahul Gandhi had earlier attacked the BJP over its MP Pragya Thakur's praise for Nathuram Godse, saying her remarks represented the "heart and soul" of the saffron party.