The United Nations Security Council is set to begin the selection process for a new secretary general next week when it holds the first informal poll on candidates in the fray.

This will include India's nominee and Under Secretary General Shashi Tharoor.

The straw poll will enable the council to determine the support each candidate enjoys among its members but will not necessarily force anyone to withdraw from the contest.

The process of finding a new incumbent to take over from Kofi Annan when he retires at the end of year will be completed by October.

Besides Tharoor, others in the field currently are Jayantha Dhanapala of Sri Lanka [Images], Surakiart Sathirathai of Thailand and South Korean Foreign Minister Ban Ki-Moon who was nominated last week.

Diplomats said that in the first of several straw polls, members will be given three choices - encourage, discourage and no opinion.

The 15 members will cast votes for each candidate separately and the result would be made known to the respective Ambassadors.

The first straw poll will not make any distinction between permanent and non-permanent members.

At a later stage, when the opinions start crystallising, the veto-wielding five permanent members will be either given ballots of a different colour.

That procedure will enable the council to determine whether any candidate attracts the veto. Diplomats said the straw poll would help attract more candidates early in the selection process.