Samajwadi Party chief and former Uttar Pradesh chief minister Mulayam Singh Yadav on Friday met Congress president Sonia Gandhi [Images] after a gap of nearly five years -- this time on the nuclear deal issue.

The last time the two leaders had met was in the first week of September 2003, days after Yadav was sworn in as the chief minister of Uttar Pradesh for the third time on August 29, 2003.

Soon after taking oath, Yadav had met Gandhi in New Delhi when the Congress announced its decision to extend ''outside'' support to the SP government.

But Yadav rejected the demand of the Congress to set up a co-ordination committee and work on the basis of a common minimum programme. Soon after, the discord between the two parties widened.

Friday's meeting took place against the backdrop of SP's declaration of clear approval of the Indo-US nuclear deal. Yadav along with his lieutenant Amar Singh met Prime Minister Manmohan Singh [Images] and United Progressive Alliance chairperson Sonia Gandhi to discuss the developments. The SP gave a clear indication of having decided to back the Congress on the deal.

The support of the SP with 39 MPs would be crucial in saving the UPA government in case the Left allies parted ways with the ruling alliance. Both the Congress and the Left have been trying to win over the SP to their side.

Bahujan Samaj Party and Uttar Pradesh Chief Minister Mayawati has already announced withdrawal of support to the UPA after accusing the central government of neglecting Uttar Pradesh and meting out step-motherly treatment to her party and the UP government.

While the SP has 39 MPs, the BSP has 17 members in the Lok Sabha, which has an effective strength of 543. The UPA currently has the support of 220 members. The Left parties, which have 59 lawmakers as a bloc, extend outside support to the government.