In a major boost to UPA Presidential candidate Pranab Mukherjee, key National Democratic Alliance (NDA) constituent Shiv Sena late on Monday assured him of its support in his bid for the top Constitutional post.

“The Sena will support Pranab Mukherjee (in the Presidential polls ),” Sena spokesperson Sanjay Raut told PTI on Monday.

The assurance was given to Mukherjee who called up Sena chief Bal Thackeray and his son Uddhav Thackeray, the party Executive President, on Monday, Sena sources said.

Sena, the oldest ideological ally of BJP, was understood to be concerned over the approach of NDA to the Presidential polls and disappointed about the fact that the alliance has not been able finalise its candidate.

Shiv Sena had supported Pratibha Patil in 2007, breaking ranks with BJP as Patil hailed from Maharashtra.

BJP and other NDA constituents had at that time backed late Bhairon Singh Shekhawat for the post of President.

The NDA’s efforts to put up a credible Opposition candidate against UPA nominee Pranab Mukherjee in the presidential race appeared to have fallen flat when  the former President APJ Abdul Kalam, who was being aggressively wooed by the BJP as well as Trinamool Congress chief Mamata Banerjee to contest against Pranab, announced his decision to opt out of the race.

Snubbed by Kalam, a desperate BJP tried to get its coalition partners to agree to back the candidature of P. A. Sangma – who has refused to bow out of the race, ignoring all appeals of his Nationalist Congress Party (NCP) – but has failed to convince them so far.

If that wasn’t enough, the BJP’s own MP Maneka Gandhi broke ranks and endorsed the candidature of Pranab. She met the finance minister in his North Block office and later told reporters that he would make an excellent President.

Though rattled by the day’s developments, the BJP doesn’t want to let Pranab’s candidature go unchallenged.

The party’s core group met late in the evening to decided its strategy. Though the final decision will be made only after the NDA meeting, the BJP has now apparently thrown its weight behind Sangma. Subramanian Swamy met the former Lok Sabha Speaker late in the evening. The party is canvassing with reluctant allies to back Sangma. Meanwhile, the NDA meeting, which was scheduled to be held on Tuesday, has been postponed.

Earlier, Kalam ended the suspense over his decision to contest. In a written statement, he said: ” I have never aspired to serve another term or shown interest in contesting the election.

Madam Mamata Banerjee and other political parties wanted me to be their candidate. Many citizens have also expressed the same wish. It reflects their love and affection for me and the aspiration of the people. I’m really overwhelmed by the support.

This being their wish, I respect it. I want to thank them for the trust they have in me… I have considered the totality of the matter and the present political situation and decided not to contest the presidential election.” Kalam’s refusal was preceded by intense political activity during the day. BJP leader L. K. Advani spoke to Kalam twice over the phone and even sent his emissary Sudheendra Kulkarni twice to his house.

Even as the BJP was making lastditch efforts to convince Kalam to contest, its key ally Janata Dal- United leader and Bihar chief minister Nitish Kumar announced that he was in favour of a consensus on the issue. Though he added that the JDU would go by the collective decision of the NDA, his stand left little doubt that the party would not back Sangma.

The JD- U was against putting up a candidate against Mukherjee even when Kalam’s name was proposed. Now that Sangma is the only choice, there’s even less likelihood of an agreement over his name since he is seen as a political lightweight.

Apart from the JD- U, the Shiv Sena is certain to oppose Sangma’s name as he is still in the NCP. A section within the BJP also feels that if Sangma also backs out, it would be very difficult for the party to save its face.