With battlelines drawn for the presidential elections, the National Democratic Alliance on Monday came out in support of Vice President Bhairon Singh Shekhawat as an independent candidate against UPA-Left nominee Pratibha Patil, but its key constituent Shiv Sena remained ambiguous on backing him.

The support to 84-year-old Shekhawat as a "non-party and independent" candidate was announced by NDA chairman Atal Bihari Vajpayee after a meeting of the opposition alliance, which felt the vice president was the "most qualified and suitable candidate for the high office."

The Shiv Sena, which has taken an "ambiguous" stance on supporting Pratibha, however, reserved its stand on backing Shekhawat, saying it will take a decision on Tuesday.

The Sena, the oldest ideological ally of the BJP, favours top posts for Maharashtrians.

"The Shiv Sena will be taking a decision tomorrow, its foundation day," senior BJP leader Sushma Swaraj said, quoting Sena leader Manohar Joshi, who attended the meeting.

There was no immediate word from the vice president, and those close to him said he was waiting for reports from Chennai, where leaders of the Third Front were holding a conclave on the presidential election.