Indian political matriarch Sonia Gandhi has refused nominate her son as her party’s prime ministerial candidate in upcoming elections, which she called a battle to save the Hindu-majority nation’s secular identity.

A day after she rejected a clamour within the Congress party to declare Rahul Gandhi as its choice for premier at polls due in May, the Italian-born Sonia told followers there was no going back on the decision.

“We took a decision on Rahul yesterday and that decision is final,” she said in a speech that was interrupted several times with shouts of “Rahul for PM!”

“We meet today to signal that Congress is ready and prepared for the battle ahead,” she told a party conclave in New Delhi.

“It will be a battle between competing ideologies, conflicting views of the history and a different vision for the future… it will be a battle for India.”

After a decade in power, Congress is lagging well behind the Hindu-nationalist opposition Bharatiya Janata Party (BJP) in opinion polls, with voters turned off by an economic slowdown and a string of corruption scandals.

Prime Minister Manmohan Singh is retiring after two terms, and the party had been expected to nominate Rahul, 43, as its choice for premier at the conclave.

But the prospects were dashed when Sonia Gandhi, the powerful party president and senior-most figure in the Nehru-Gandhi dynasty, opposed the move at a meeting on Thursday night.

Rahul remains the party’s chief election strategist.

Analysts have said the BJP’s decision to project the divisive Narendra Modi as its choice for premier could limit its room for manoeuvre in post-election coalition negotiations – a trap that Sonia Gandhi is keen to avoid.

There has also been press speculation that Congress’s expected defeat will be so comprehensive that the Gandhi family fears it could kill off Rahul’s nascent political career.

But the clan’s star power remains high and many in the party see Rahul as their best hope, despite his well-documented reservations about following in the prime ministerial footsteps of his father, grandmother and great-grandfather.