Mike Wooldridge in Delhi: Only remarkable climbdowns would help her to form a government

Mrs Gandhi told the president on Friday she had support from 233 MPs, but was still 40 votes short of the majority needed to form a government after the collapse of the Hindu-nationalist coalition last Saturday.

She suffered a setback earlier in the day when potential ally Mulayam Singh Yadav, who has 20 MPs in his party, refused to support her bid.

She had set herself a Friday deadline for forming a minority Congress government with enough outside support to operate.

"The number does not add up to the requisite number," she said, "but I have been told to do whatever we have to do as soon as possible."

Politicians are under pressure to come up with some workable power sharing arrangement because the Indian public is thought to have little appetite for another general election, coming so soon after the last one just 13 months ago.

Sonia Gandhi: wants to finish exercise quickly

Mrs Gandhi said after her meeting with the president she still hoped "secular forces" would work with her to prevent the Hindu nationalist Bharatiya Janata Party (BJP) government returning to power.

But she would consider other options than leading a minority Congress-only government, including a coalition government led by someone else, she said.

Prime Minister Atal Bihari Vajpayee's coalition, led by the BJP, said if Congress fails to deliver the BJP should be able to try again. The BJP remains the largest party in parliament and claims support from 270 members.

"There is no need for fresh elections. We are already in the field," Vajpayee said after a meeting of the parliament members from his alliance.

However, quick elections are seen as a strong possibility.

Earlier on Friday the influential north Indian political leader, Mulayam Singh Yadav, wrote to the Indian president saying he could not support Congress or the BJP.

"The party is of the opinion that both the BJP and Congress are responsible for ruining the country," he said.

The BBC's Delhi Correspondent Daniel Lak says the onus is now on Congress to drop its bid for a minority single party administration and opt instead for a coalition.

Regional and left backing

The BBC's Mike Wooldridge: "Congress might be doing some climbing down"

Congress had won backing from most of the so-called "Third Front" comprising regional, caste-based and left-wing parties.

Its most important gain came on Thursday when the south Indian-based party, the All India Anna Dravida Munnetra Kazhagam (AIADMK), joined Sonia Gandhi. It was the withdrawal of AIADMK support that triggered the crisis leading to the downfall of the BJP-led coalition.