Mumbai: In a watershed development in state politics, the Congress will support a Shiv Sena-led government in Maharashtra, sources in all state parties said.

The development came after a hectic day crowned by Congress Interim President Sonia Gandhi first speaking with Nationalist Congress Party President Sharad Pawar, then faxing a letter of support to the Shiv Sena, followed by a copy being faxed to the Raj Bhavan, sealing the tripartite deal.

Earlier, Pawar met Shiv Sena President Uddhav Thackeray in Mumbai to finalise the understanding, and later Thackeray spoke with Gandhi to make a formal request for support.

Armed with support letters from both Congress and NCP, a high-level Shiv Sena delegation comprising Aditya Thackeray, Eknath Shinde and other senior leaders has already reached the Raj Bhavan to meet Governor B.S. Koshyari to stake their claim to form the government.

According to tentative reports, the Sena may be able to prove the support of more than 170 legislators, but it is not clear who would be elected as Chief Minister.