Senior leaders of India's Congress party are meeting Ms Sonia Gandhi today in an effort to pressure her to reconsider her decision to turn down the prime minister's job.
Some senior figures even quit their party posts in protest at the decision yesterday by their Italian-born chief, it was reported.
"We are joining the rest of the Congress party workers across the country who want her to become prime minister," Ms Ambica Soni told reporters. She said senior Congress leaders would meet Gandhi this morning.
"The mood is very volatile, we are trying our best," Ms Soni said as distraught Congress workers smashed window panes at the party office to display their unhappiness over Ms Gandhi's decision.
Earlier a key Congress party ally said it was likely to inform President Abdul Kalam today that it is in a position to form a government.
"The claim would be made by the end of the day," Mr Sitaram Yechury, spokesman of the Communist Party of India (Marxist), told reporters after a meeting with Congress chief, Ms Sonia Gandhi, a day after she formally declined to serve as prime minister.
Congress has since urged party members to support former finance minister Mr Manmohan Singh as prime minister.
Mr Singh, architect of India's economic modernisation reforms, is the front-runner to lead the world's largest democracy
India's markets, spooked by anti-reform comments by left-wing parties supporting the Congress without formally joining its coalition, welcomed Mr Singh's possible rise to power. He would become India's first Sikh prime minister.
Mr Singh commands respect for his integrity and intellect, but will need sharp political skills to manage partymen - who have looked only to the Nehru-Gandhi dynasty to lead - and a disparate crew of allies with their competing demands.