The Yemeni opposition announced the creation of an umbrella council to take over transitional power, a move seen as increasing pressure on President Ali Abdullah Saleh to step down.
The council was unveiled late Wednesday, a day after Saleh said in a televised address that he would return "soon" to Yemen from Saudi Arabia, where he has been receiving medical treatment for injuries suffered during an attack in Sana'a in June, DPA reported.
The launch of the 143-member National Council was criticized Thursday by Tareq al-Shami, a spokesman for the ruling General Popular Congress Party.
"The opposition's deal on establishing this council is a step tantamount to declaring the death of the Gulf initiative," he said, referring to a plan brokered by the Gulf Cooperation Council countries for carrying out a constitutional power transfer in Yemen.
Al-Shami accused the opposition of inciting "a conspiracy against the legitimate regime" of Saleh.
The council comprises opponents of Saleh within Yemen and outside.
"The unity of the revolutionary powers at this historic moment is set to help pave the way for the emergence of a new Yemen free from misery," said Mohamed Salem, who presided over the gathering.
He said the council was seeking to unify "efforts to remove the remnants of the autocratic, dynastic rule" of Saleh.
An estimated 1,000 representatives from the opposition attended the rally in Sana'a.
Millions of Yemenis have been taking to the streets since February demanding Saleh's ouster.