Battlelines were drawn on Thursday for the August 10 vice presidential poll at the end of withdrawal of candidature, setting the stage for the triangular contest.

Hamid Ansari of United Progressive Alliance-Left, Najma Heptulla of National Democratic Alliance and Rasheed Masood of the Third Front are in the race for the second highest office.

Rajya Sabha sources said that as the deadline for withdrawal ended today, all the three aspirants remained in the fray.

Rajya Sabha Secretary General Yogendra Narain is the Returning Officer for the vice presidential election.

Ansari is 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.