Libyan rebels, meanwhile, expect to take part in a plenary session of the meeting of senior international diplomats and said they will be seeking full recognition.
Outgunned rebel forces with the backing of Western air and sea strikes supported by Gulf states have held onto eastern Libya, yet they have failed to make significant inroads in the west, towards Gaddafi’s power base in Tripoli.
The North Atlantic Treaty Organisation, in charge of military operations in Libya for almost two weeks, is sticking to UN Security Council Resolution 1973 which authorises action to protect civilians in Libya but not regime-change.
Libya risks partition if Gaddafi survives.
A ceasefire as proposed by the African Union, which has so far kept out of the international contact group which is to convene in the Qatari capital, would keep Gaddafi at the helm in Tripoli.
Rebels have rejected that initiative.
British Foreign Secretary William Hague and Qatari Prime Minister Hamad bin Jassem Al-Thani are to co-chair the Doha meeting, to be attended by the international community and the rebels’ Transitional National Council (TNC).
Two-way talks
The forum is being held to discuss “the situation in Libya and support the people of Libya”, according to the official agenda.
“We shall not accept or listen to any proposal for a political solution if it does not stipulate in its first clause the departure of Gaddafi and his sons from Libya,” the TNC’s Mahmud Shammam said in Doha.
“We want to move from the de facto recognition of the council to an internationally-recognised legitimacy,” Shammam also told AFP on the eve of the forum.
French foreign ministry spokesperson Bernard Valero played up the TNC involvement in the one-day meeting.
“Not only will they be there, but – and this should be checked with the Qataris – unlike London, where they were on the sidelines, they will appear before the contact group,” he said.
On March 29 in London, the TNC was kept out of the plenary session, although its envoys held two-way talks in the British capital with several world powers.
The contact group is made up of Western countries such as Britain, France and the United States as well as Arab members including Qatar, Jordan and Morocco, the United Nations, Arab League and Nato.
Libyan former foreign minister Musa Kusa, who arrived in Britain unexpectedly at the end of March and quit, was on Tuesday headed for Qatar to hold talks ahead of the contact group meeting, the Foreign Office said.
Dark secrets
The TNC said he was not connected to the rebels in any way, unlike senior defectors. “He is the black box of Gaddafi’s regime,” holding many dark secrets about the Tripoli government, said a spokesperson in the rebel stronghold of Benghazi, in eastern Libya.
William Burns, the number three at the US State Department, is to travel to Doha to represent the United States, which together with France and Britain launched strikes against Gaddafi’s forces on March 19.
But Washington pulled its combat jets from the frontline last week, leaving the bombing to European and Canadian allies as it withdraws into a support role by providing surveillance and refuelling planes.
A divergence of priorities between the United States and its coalition allies could derail operations in Libya.
On Monday, US Secretary of State Hillary Clinton put “non-negotiable” demands including a ceasefire ahead of the departure of Gaddafi, who has been in power for nearly 42 years.
In contrast, France and Britain are insistent he must go.
William Hague emphasised on Tuesday that “to have any viable, peaceful future for Libya, Colonel Gaddafi needs to leave”, while calling for Nato military operations to be stepped up.
“Nato must fully play its role, and it is not doing so sufficiently,” French Foreign Minister Alain Juppe said.