BEIRUT, Dec. 7 (Xinhua) -- Hezbollah leader Sayyed Hassan Nasrallah will give a speech Thursday evening, addressing protestors camping outside government headquarters in Downtown Beirut, the group's al-Manar TV reported.

    Nasrallah will speak at 8:30 p.m. (1830 GMT) Thursday, one day after anti-government protestors led by Hezbollah announced plans to launch another mass demonstration on Sunday in a bid to topple Prime Minister Fouad Seniora's government.

    The opposition on Wednesday called on the Lebanese to participate in a demonstration Sunday in central Beirut at 3 p.m. (1300 GMT) to wish "that this will be a historic and decisive day on which our voices are heard."

    Lebanese opposition supporters have been staging an open-ended sit-in for seven days in Beirut in a bid to topple Seniora's government and form a national unity cabinet.

    The current political turmoil was triggered by last month's resignation of six pro-Hezbollah ministers after Seniora and his supporters rejected Hezbollah's demand for enough portfolios to have veto power over cabinet decisions.