Kofi Annan has this week begun his last United Nations General Assembly session as Secretary General. He must stand down by the end of the year, and the race to succeed him is gathering pace.

Seven people have already declared their candidacy, but it is possible that Mr Annan's successor will not be among them. There is still time for others to throw their hats into the ring.

Traditionally, the UN Security Council recommends a candidate and the 192-member General Assembly approves the choice.

Owen Bennett-Jones hosts a special debate for the BBC World Service programme Newshour, featuring four of the candidates: Shashi Tharoor, Dr Jayantha Dhanapala, Dr Vaira Vike-Freiberga and Ashra Ghani Ahmadzai.

Listen to the programme

This programme was first transmitted on Wednesday 27th September 2006.