How was Gandhi persuaded that, as one government official put it, "if you are not growing you are distributing poverty"?
For one thing, the economy was in trouble. Growth had dropped to its lowest clip in three years, the fiscal deficit was blowing past official targets, and the government was under heavy fire for sitting on its hands as the crisis mounted.
With Mukherjee gone from the Finance Ministry, Singh and Chidambaram made their move, warning Gandhi of a possible slump in the rupee and even a repeat of 1991, sources said.
"There were three meetings over about four weeks ... to tell her that if we don't do all this it will be bad politics," said the senior government official.
Singh also tackled Gandhi at length on the issue in July during a flight from Delhi to Assam.
Adding his voice at a separate meeting, Commerce Minister Anand Sharma explained to Gandhi that opening up to global supermarkets like Wal-Mart Stores Inc could tame the corruption that plagues the state-run food distribution network - a compelling argument after two years of graft scandals that have damaged her government.
When Gandhi returned in September from a medical check-up abroad, the stage was set for 'big bang Friday'.
And although the reforms triggered the walkout of key coalition partner Trinamool Congress (TMC) from the government, reducing it to a minority, she has resisted calls for a U-turn and even plans to join a street march in favour of the retail sector reform.
Gandhi's ambition in all this is to ensure that the Congress party returns to power in 2014, with her son - Rahul - at the helm of the government after eight years waiting in the wings.
"What she is concentrating on is really the need to be re-elected," said MJ Akbar, a former Congress party lawmaker and once a trusted Gandhi family insider. "The only thing wrong about this reforms business though is ... they left it too close to the election."
Image: Congress General Secretary and Member of Parliament Rahul Gandhi (second left) and Indian Prime Minister Manmohan Singh (left) watch as Congress Party President and United Progressive Alliance (UPA) Government Chairperson Sonia Gandhi (third left) casts her vote during the election for Vice President.