Several officials, who asked to remain anonymous, said there had been considerable change in the finance ministry, where Chidambaram was working to shake off the dithering seeping down from policy-makers.
In a series of interviews, they described him as a no-nonsense man who is constantly questioning, hands-on, meticulous and intolerant of people who could not manage their time.
India's economic policy-making has been blocked for months by confusion, mis-steps and political gridlock.
While the timing of big-bang reforms remains uncertain, the Harvard-educated Chidambaram is trying to work around bickering politicians and is drawing up a package of smaller measures to stop the rot, such as improving tax collection, fast-tracking stalled infrastructure projects and asking state banks to ease lending to small manufacturers.
His ministry is ratcheting up pressure on wayward coalition allies of the ruling Congress party to agree on a long-overdue increase in heavily subsidised fuel prices.
Ministry officials warned for the first time last week that if the hikes did not take place soon, spending cuts might be necessary to keep the budget deficit under control.
The cabinet may consider making a move on fuel prices this week.