The United Nations Security Council will hold two quick straw polls on Thursday and on October 2 as it intensifies its search for the next Secretary General to replace incumbent Kofi Annan at the end of the year.

The straw poll on Thursday will not show if any candidate has a veto against him or her but the exercise on October 2 will bring out if a candidate has attracted a veto and that, diplomats say, could set the stage for withdrawal of candidates who feel that they stand no chance, thus narrowing field among the seven but opening way for others to be introduced.

India's Shashi Tharoor is among the seven candidates in the field. Former Afghan Finance Minister Ashraf Ghani and Latvian President Vaira Vike Freiberga, first woman to join the race, will contest in the straw poll for the first time.

While in Thursday's poll, all members would get similar ballots, in that of October 2, veto-wielding permanent members -- the US, Britain, France [Images], Russia [Images] and China -- will have different coloured ballots. A candidate needs nine votes with no veto to be recommended to the General Assembly election for a five-year term.

Asked why two polls have been scheduled so close, Council diplomats said the members could see standing of various candidates and then come back with fresh instructions from their government, hinting that the October 2 poll might prove decisive.

Thursday's poll will be held under the presidency of Greece and Monday's exercise will be under Japan [Images]ese presidentship. Japan, diplomats say, is very keen that the new Secretary General be selected under its presidency.

Some diplomats said that negotiations are on between the five permanent members to float their own candidate should no current contestant get all 15 votes or each has veto from one member or the other.

South Korean Foreign Minister Ban Ki-Moon, who was the front-runner in the last two polls, has asserted in interviews that he would get 15 positive votes, saying that he has got very encouraging response from the permanent members, whose voice will prove decisive.

In the last straw poll, Moon [Images] had got 14 positive votes and one negative but was it not clear if the one who opposed him was a permanent member with veto. Tharoor was placed second.

Also in the field are Deputy Prime Minister of Thailand Surakiart Sathirathai, Jordanian Prince Zeid al-Hussein and Sri Lanka's [Images] Jayantha Dhanapala.