NEW DELHI, May 17: Indian President A.P.J. Abdul Kalam on Monday invited Congress president Sonia Gandhi for talks on the formation of the country's next government. She will be sworn in as prime minister on Wednesday.

Earlier in the day, the communist-led Left Front decided to support the government without being part of the cabinet. With all the new and old coalition partners, Ms Gandhi has more than 320 MPs in the 539-strong Lok Sabha, short by four of its full complement of elected MPs.

"Our support to Mrs Sonia Gandhi is rock solid. There should be no doubt that we will never again allow the Bharatiya Janata Party to form a government in this country," A.B. Bardhan, general secretary of the Communist Party of India told reporters.

He gave no reason why the Left Front would not participate in the government. Ms Gandhi's left-leaning coalition will be known as the United Progressive Alliance (UPA).

Outgoing prime minister Atal Behari Vajpayee's National Democratic Alliance partners on their part decided to boycott Ms Gandhi's swearing in, saying it was unacceptable to them that the country was going to get a prime minister of foreign origin.

Mr Vajpayee would however attend the ceremony 'as a courtesy to the president'. Ms Gandhi held several rounds of talks with her allies on Monday and there were rumours that she had offered to step down as the candidate because of the NDA's objections to her foreign origins. She was persuaded to lead on.

"After holding a second round of talks with allies on Monday evening, Congress chief Sonia Gandhi has decided to be sworn in as the prime minister of India on Wednesday, May 19," a party official said.

Rashtriya Janata Dal chief Laloo Prasad Yadav, National Congress Party chief Sharad Pawar, Dravida Munnetra Kazhagam chief Muthuvel Karunanidhi, Marumalarchi Dravida Munnetra Kazhagam chief Vaiko and Lok Janshakti chief Ramvilas Paswan were some of the prominent allies who held talks with Sonia Gandhi.

The Congress chief will meet President Kalam on Tuesday after he invited her for talks on government formation. Senior party leader Pranab Mukherjee, who addressed the gathering with Manmohan Singh after the meeting, said: "There is no scope for any rumour now and the time of the meeting will be communicated to you."

Laloo Yadav reacted sharply to rumours that Sonia Gandhi would nominate senior party leader Manmohan Singh as the prime minister of the new coalition government, saying they were spread by those who had circulated that 'Ganeshji drank milk'. This was a reference to rumours some years ago, apparently spread by the Hindutva forces, that images of the Hindu deity were drinking milk offered by devotees.

A presidential communique said Mr Kalam had sent a letter to Ms Gandhi at 1700 hours requesting her to meet him 'today or tomorrow morning for discussions as per her convenience'.

A statement by the Left Front said: "The Left Parties have registered a big success by winning 61 seats. This is a recognition by the people of the consistent role played by the Left in defence of secularism, the interests of the working people and opposing the growing imperialist influence."

It said the verdict was for the formation of a secular government at the Centre. This was one of the main aims of the Left platform in the election campaign. "The Left Parties have, therefore, decided to extend support to the Congress-led coalition government, which is to be formed under the leadership of Sonia Gandhi.

While extending support from outside, the Left Parties will ensure that any machinations by the BJP and the communal forces to destabilize the government are foiled." The policy direction of the new government is going to be determined with the formulation of a common minimum programme.