NEW DELHI (AFP) - The path is clear for India's Gandhi family scion Rahul to become the Congress party's next prime ministerial candidate, following premier Manmohan Singh's announcement on Friday that he will step down before this year's polls.

Mr Rahul, 43, is already number two in the Congress, behind his mother Sonia who is party president, and he is chief strategist for the national elections.

The party originally had no plans to declare its candidate for the top job before voting, but newspapers are now speculating that Mr Rahul will be promoted as early as a meeting on Jan 17.

Congress faces a resurgent opposition Bharatiya Janata Party (BJP), running a successful campaign centered on its candidate Narendra Modi.

Media-shy bachelor Rahul has no ministerial experience and has never sought a government job, but his elevation is seen internally as a natural progression in a party dominated by his family.

However, the son, grandson and great-grandson of former prime ministers faces a difficult task in turning around the fortunes of Congress in the upcoming polls and doubts still remain about his appetite for the job.

He accepted the position of number two in the party in January last year, raising hopes he would play a larger public role in setting policy and priorities.

But since then, he has only intermittently taken the spotlight and Congress suffered a string of state election defeats in the final months of 2013 despite him being projected as the party's new face.

As Congress MPs face stinging reverses in the polls, dissent is reportedly mounting although none have had the courage to publicly question his anointment or propose rival candidates.

"My frustration is that he is too forward-looking. He is talking of structure, systems," said Rural Development Minister Jairam Ramesh last year in the most critical public comments to date.

In a rare moment of public leadership, Mr Rahul wrong-footed the entire government and publicly contradicted Mr Singh in September by denouncing the government's intention to move a decree to shield lawmakers convicted of corruption.

Since taking up senior roles in the party, Mr Rahul has mostly focused on building up the youth wing and has talked broadly about the need to refresh and rebuild the party.