NEW DELHI: India's Sonia Gandhi stalled a push on Thursday for her son Rahul to be named the ruling Congress party's candidate for prime minister, saying such a move was against tradition.

There had been widespread expectations that Rahul would be formally declared as the party's choice for premier at a meeting in the capital New Delhi on Friday.

But party spokesman Janardan Dwivedi said that Sonia Gandhi, who is the party's powerful president, had made clear her opposition to such a move at a committee meeting in which Rahul indicated he was prepared to take on the mantle.

Her intervention is almost guaranteed to extinguish Rahul's chances of being anointed prime ministerial candidate on Friday.

“All the members of the CWC (Congress Working Committee) wanted him to be announced as the PM candidate but the Congress president intervened,” Dwivedi told reporters.

“She said: 'This is not the party's tradition (to announce its PM candidate before elections). Just because some party has declared the PM candidate, does not mean that Congress will do the same'.”

There has been a growing push within Congress to name the 43-year-old Rahul as candidate for prime minister after the main opposition Bharatiya Janata Party (BJP) formally declared Gujarat Chief Minister Narendra Modi as its choice.

Since Modi's elevation, the BJP has stretched its lead in the polls over Congress and the nomination of Rahul this week was seen as a desperate bid by the ruling party to avert humiliation when the world's largest democracy votes in an election due by May.

Sonia Gandhi, who is the widow of the slain former prime minister Rajiv Gandhi, is seen as India's most powerful politician.