Pushkar, who was upset over an alleged extra-marital affair between Tharoor and a Pakistani journalist, was found dead in a room in the Leela Palace hotel yesterday.
Pushkar and Tharoor were at the centre of a raging controversy in the last few days when reports emerged that she was upset over reported text and tweet messages between her husband and Mehr Tarar, the Pakistani journalist.
"It is sad but Tharoor won't be able to attend the festival today," Festival producer Sanjay Roy said.
Tharoor was scheduled to participate in a session titled 'The paradoxes of development and growth' under the ongoing 'Democracy dialogues' series at the festival.
He was to also launch a book titled Travails with Chachi written by Salman Khurshid's wife, Louis Khurshid.
Tharoor was also sated to inaugurate the prize ceremony for the $50,000 DSC prize for South Asian Literature.
"Book launch would be done by someone else now. We were at a musical evening when we got the sad news. Its sad," Roy said.
In his last Twitter post yesterday the Union Minister had also said that he would not have been able to attend the Festival due to illness of his wife Sunanda Pushkar.
"My wife's illness means i need to be with her & will miss all 5 events of #JaipurLitFest 2014." This was the last tweet posted by the Union Minister last evening before her death later at night.