Mumbai, Apr 17 (IANS): Shiv Sena chief Uddhav Thackeray Wednesday called on the Bharatiya Janata Party (BJP) to take into confidence all NDA constituents before finalising its prime ministerial candidate.

In a strongly worded editorial in the party mouthpiece Saamna, Thackeray said the BJP has the right to nominate its candidate for prime minister but it could not take a unilateral decision on the issue.

"A section of the party is promoting Narendra Modi as PM candidate. Is it really so? Top leaders like Rajnath Singh, L.K. Advani and Sushma Swaraj must clarify on this once and for all," Thackeray said.

He added that the ruling United Progressive Alliance (UPA) had publicly stood behind Manmohan Singh as the next prime ministerial candidate though they may hold differing views in private.

In the opposition BJP-led National Democratic Alliance (NDA), on the other hand, there are several claimants, Thackeray noted, likening the situation to Arjun's chariot led by several horses, each important.

The scramble among various prime minister aspirants in the NDA even before the elections have been announced was amusing, the Shiv Sena leader said, urging all constituents of the alliance to exercise restraint on the issue.

He said political pros and cons must form the basis of any decision that the NDA takes.

"If on account of any candidate, the NDA gains five-ten seats, old friends who stood with the BJP for years may be distanced and result in the loss of many more seats," Thackeray warned.

The Shiv Sena has in the past expressed its willingness to support Sushma Swaraj as the next candidate for prime minister as the late party chief Bal Thackeray wished for.