Pressure has been mounting on Arjun Singh from his Congress colleagues to speak up about Warren Anderson and clear the air over then Prime Minister Rajiv Gandhi's role in the Union Carbide chief's escape.
However, the former Madhya Pradesh chief minister maintained a stoic silence. On Saturday, he backed out from an event organised by a media group to felicitate him with a lifetime achievement award for his contribution to the Urdu language.
The party leaders want him to break his silence so that "names of others are not unnecessarily dragged" into the issue.
Congress Working Committee member Satyavrat Chaturvedi recalled that Arjun Singh had earlier admitted taking the decision at the state level and without any instructions from the Centre.
"Arjun Singh should break his silence and come forward to tell whether he stands by the three statements he had made after Anderson left the country, which clearly bring out the fact that the then Prime Minister Rajiv Gandhi had no role into it," he said.
"On December 8, 1984, Arjun Singh had said that Anderson was allowed to leave the country because the police felt his presence was not required," Chaturvedi recalled.
Congress leaders pointed out to news reports of that period which suggested that Rajiv Gandhi was unaware of developments related to Anderson's arrest and subsequent release.
The fact that the Cabinet Committee on Political Affairs in its meeting, where Arjun Singh was present, on December 9, 1984, did not discuss the Anderson issue give credence to such reports, a leader said.
"He briefed the PM only in the evening."
Many Congress leaders believe Arjun Singh will break his silence only when he desires.
"It is impossible to force him to speak up," said a functionary.
The government is expected to come up with a clarification on the issue shortly.