Terrorists had planned to carry out a blast at Matoshree, the home of Thackerays in 1989, forcing Shiv Sena patriarch Bal Thackeray to direct every member of the house to shift to a safer place for a few days, former Sena member Narayan Rane claims.
Sharad Pawar, who was the chief minister of Maharashtra then, called Bal Thackeray's youngest son Uddhav Thackeray and informed him about the threat, the BJP-backed Rajya Sabha member says. He also claims that Bal Thackeray was on the hit-list of Khalistanis, who had managed to find support in Mumbai.
Mr Rane mentions these incidents in his memoir "No Holds Barred: My Years In Politics".
On March 19, 1988, Bal Thackeray organised a press conference, where he circulated a questionnaire seeking assurances from the torchbearers of the Sikh community in the city that they had not been financing the movement's activities, Mr Rane says.
According to him, Bal Thackeray declared at the presser that if the Sikhs continued to fund extremism, he would ensure that they were socially and economically boycotted in the city.
He says the Shiv Sena lost the Maharashtra legislative assembly elections in 1989, and the defeat put Bal Thackeray in an even more vulnerable position, since state security was controlled by the Congress.
"He amped up protection at Matoshree and everyone was on high alert. In the midst of all the tension, newly-married Uddhavji received an unexpected phone call from Chief Minister Pawar Saheb, who asked him to come and see him immediately. Alone - he had specified," Mr Rane writes.
Sharad Pawar shared a close camaraderie with Bal Thackeray and "owing to that relationship, he informed Uddhav about the plot.
Sharad Pawar, says Mr Rane, also informed that he was "worried because insiders were involved - insiders from Matoshree, the state police force, and even the home ministry".
"Pawar Saheb said the D-Day was two days away and offered the Thackerays increased police protection, adding that he should keep the information within the family," claims Mr Rane in the book, co-authored with Priyam Gandhi-Mody and published by HarperCollins India.
Uddav Thackeray then discussed Sharad Pawar's information with his father, who instructed every member to find a safe house for a couple of days and steer clear of Matoshree.