Nomination papers filed by three candidates for the August 10 vice presidential poll -- Mohammed Hamid Ansari of United Progressive Alliance-Left, Najma Heptulla of National Democratic Alliance and Rasheed Masood of the Third Front -- were on Tuesday found valid on scrutiny.

Out of 33 persons who had jumped into the fray, the nomination papers of all other persons were rejected on different grounds, Rajya Sabha sources said.

Rajya Sabha Secretary General Yogendra Narain is the returning officer for the vice presidential election.

While Ansari and Heptullahad filed their papers on Monday (the last day for filing papers), Masood had completed the formalities last week.

Though the last date for withdrawal is July 26, the stage seems to be all set for a triangular contest on August 10 with Ansari being way ahead of his rivals in an all-Muslim race as numbers are heavily loaded in his favour to succeed Bhairon Singh Shekhawat.

The electoral college for the poll comprises members of the Lok Sabha and the Rajya Sabha.

The UPA along with Left parties as also Bahujan Samaj Party commands the support of 425 of the total 788 members.

The NDA has the backing of 240 members, while the stand of two of its allies -- Shiv Sena and Trinamool Congress -- is still not known.

The Third Front, formally known as United National Progressive Alliance, has 81 members.