India's patrician finance minister P. Chidambaram is fast emerging as a potential prime ministerial candidate amid fresh doubts about the aspirations of ruling party heir-apparent Rahul Gandhi.

Last week, Rahul, the shy scion of the Nehru-Gandhi clan and long presumed to be a Congress prime minister-in-waiting, declared that the top job was "not my priority" and that he wanted to focus on building up the party.

The question of whom the embattled ruling Congress party could run in Rahul's place has become urgent with elections due by May 2014 and 80-year-old Prime Minister Manmohan Singh expected to step down.

The name on many people's lips is pro-market reformer Chidambaram -- a wealthy southern lawyer from a land-owning family with an MBA from Harvard. He has presented eight national budgets in a two-decade political career.

"Prime Minister Chidambaram?" was the headline splashed across the latest cover of national news magazine Outlook as it delved into what has become the hottest topic of gossip among the capital's elite.

Chidambaram, who was renamed to be finance minister last year and helped drive through a reform blitz in September, heads "the probable list", said leading news portal Firstpost.

The politician, named as home minister to help rebuild India's security confidence after the deadly 2008 Mumbai attacks, has become the go-to trouble-shooter for the corruption-tainted Congress.

Analysts note that the intentions of 42-year-old Rahul, recently named to the number two post in Congress behind his mother Sonia, were still unclear but his perceived dithering is in danger of harming the party's prospects.

After a second term in power characterised by corruption scandals and a massive slowdown in the economy, Congress's poll ratings are dismal and it is in need of reinvigoration, they say.

The Italian-born Sonia, who led the party to its 2004 return to power, famously declined the prime minister's job -- winning adulation for her act of "renunciation" -- while remaining India's most powerful politician.

"He (Rahul) could do a Sonia -- heed his 'inner voice' and step aside for someone else," said economist T.C.A. Srinivasa Raghavan, a former Reserve Bank of India consultant.

"The only person who meets the bill is Chidambaram. He alone has the seniority and the (political and economic) track record," he said.

Singh, whom Sonia named prime minister in her stead nine years ago, is a renowned and apolitical economist with no mass political base.

Similarly, note analysts, Chidambaram is not a mass leader and has no base to challenge the Gandhis in case either Rahul or his sister, Priyanka, want to seek the premier's job later on.

The pool of other Congress contenders for the job has been curtailed by what has been seen as a desire by party brass to ensure Rahul has a clear run at claiming the throne.

The Nehru-Gandhi clan have dominated post-independence India, with Rahul's great-grandfather, grandmother and father all serving as prime minister.

At 67, Chidambaram is also young by India's political standards where many politicians are in their 70s or 80s, and his pro-market credentials could be useful in an election likely to be fought largely on the economy.

His most likely challenger from the national opposition will be Narendra Modi, Gujarat state's controversial chief minister from the Bharatiya Janata Party (BJP), as well as the increasingly powerful regional and local parties.

But critics say Chidambaram can also be arrogant and dismissive, and add alleged poll rigging charges stemming from his 2009 election could cast a cloud.

Also, his command is limited of Hindi, the most widely spoken vernacular language, which restrains his appeal to the rural masses of northern India and his ability to perform as an election campaigner.

Chidambaram himself has laughed off suggestions that he might be a prime ministerial aspirant, saying recently: "I know my limitations."