Update 1.54pm: Zimbabwe's ruling party has presented a motion to impeach President Robert Mugabe, seconded by opposition party MDC.
Mr Mugabe, 93, is accused of allowing his wife to "usurp" power and of being too old to rule.
He has been in charge since the end of white minority rule in 1980, but the military moved in last week after he fired his deputy and appeared to position his unpopular wife to succeed him.
It is not clear how long impeachment would take, though the ruling party has said it could vote Mr Mugabe out as early as tomorrow.
Politicians from both houses of Parliament are now relocating to a larger venue.
Earlier, opposition leader Morgan Tsvangirai told a crowd outside Parliament that a "democratic Zimbabwe cannot be built by another un-democratic process".
Mr Tsvangirai said the culture of the ruling party "must end" and everyone must put their heads together and work toward free and fair elections.
He added: "Now the question is, how do we end Mugabe?"
Meanwhile, recently fired vice president Emmerson Mnangagwa said Mr Mugabe should acknowledge the nation's "insatiable desire" for a leadership change and resign immediately.
He said: "The people of Zimbabwe have spoken with one voice and it is my appeal to President Mugabe that he should take heed of this clarion call and resign forthwith so that the country can move forward and preserve his legacy."
Zimbabwe's ruling party is set to begin impeachment proceedings against President Robert Mugabe.
A party official, meanwhile, says government ministers have been instructed to boycott a cabinet meeting called by the president.
Ruling party chief whip Lovemore Matuke said minutes before the cabinet meeting was expected to start that ministers have been told to instead attend a meeting at party headquarters to work on the impeachment.
Parliament resumes today.
Mr Mugabe's chief secretary yesterday summoned ministers to the cabinet meeting at State House, the president's official residence.
Mr Mugabe is finding himself increasingly isolated.
The military last night said the vice president he recently fired, sparking the political turmoil, will return to Zimbabwe "shortly" and has made contact with Mr Mugabe.