At the behest of President Ali Abd Allah Salih, a group of opposition leaders, clerics and tribal chiefs will on Wednesday return to the Maran area in Saada province, where Husain Badr al-Din al-Huthi and thousands of his supporters are besieged, the source said on Tuesday.
Mediation efforts last month failed to resolve ongoing clashes between al-Huthi's men and the army. An MP involved in the aborted talks accused elements within the army of undermining efforts to end the crisis peacefully.
The newly formed group will try to persuade al-Huthi to turn himself in with the guarantee that he will be judged fairly, the source said.
The group includes al-Huthi's brother Yahya, who is an MP, and Abd al-Karim Jadban, a co-founder of al-Huthi's Faithful Youth organisation, formed in 1997 as a breakaway from the Islamist opposition movement, al-Haq.
Sanaa will "request that the military command on the ground cease operations to help the new mission to reach al-Huthi and his supporters" in their stronghold, the source added.
The launch of the mediation effort, however, did not stop the Yemeni authorities from commencing legal proceedings against a senior judge accused of supporting al-Huthi's uprising.
Muhammad Luqman, who heads a court in the western region of Haraz, was formally charged with "inciting armed insurrection", "inciting civil disobedience" and "calling for the replacement of the republican regime with an imamate (a Shia theocracy)" at the opening of his trial in Sanaa.
Al-Huthi accuses the government
of hounding him to please the US
Luqman, who was stripped of his judicial immunity on 10 July, was represented by some 20 counsels, including the head of the lawyers' union, Abd Allah Rajah.
Judge Muhsin Alwan adjourned the trial until Sunday.
The clashes between the army and al-Huthi's supporters have so far left some 300 people dead.
Al-Huthi, a preacher from the Zaidi community, said last week that the conflict was a result of his anti-US stand and accused Salih of seeking "to please the United States at the expense of his own people".