South Africa's President Jacob Zuma and his Angolan counterpart Joao Lourenco will fly to Zimbabwe tomorrow for talks aimed at resolving the crisis over President Robert Mugabe's refusal to step down, a journalist with South Africa's public broadcaster has tweeted:

Regional leaders met in Angola today for an emergency meeting of the regional bloc, the Southern African Development Community (Sadc), to discuss the crisis.

A protest is taking place outside Zimbabwe's parliament to demand free and fair elections after President Mugabe's removal from office, a pro-democracy activist has tweeted:

Zimbabwean MPs will debate impeaching proceedings against President Robert Mugabe at the Rainbow Towers Hotel, a senior member of the ruling party, Patrick Chinamasa, has said, according to this tweet:

And the reason for moving the historic debate to a hotel?

The hotel, formerly known as Sheraton Harare, has a conference facility.

The motion to impeach Zimbabwe's president Robert Mugabe was moved by ruling party MP and War Veterans Association leader Chris Mutsvangwa, and was seconded by opposition MP James Maridadi, the speaker is quoted by Reuters news agency as saying.

Other reports says it was Mr Mutsvangwa's wife who proposed the motion.

An MP from Zimbabwe's ruling Zanu-PF party has shared a picture of herself and colleagues at the parliamentary session called to start impeachment proceedings against President Robert Mugabe:

Jessie Majome, who represents a constituency in the capital, Harare, had earlier shared a picture of herself holding anti-Mugabe posters:

Zimbabwe's parliament has opened for a historic session to start impeachment proceedings against President Robert Mugabe.

"This motion is unprecedented in the history of post-independence Zimbabwe," Parliament speaker Jacob Mubenda said, AFP news agency reports.

He then adjourned parliament saying there would be a joint session of the House of Assembly and the Senate later today to debate the motion, a Twitter account which monitors Zimbabwean media says:

MPs allied with Zimbabwe's President Robert Mugabe and his wife Grace are also in parliament for the start of impeachment proceedings, a group which monitors parliamentary activities has tweeted:

Crowds have gathered outside Zimbabwe's parliament to witness the dramatic move to impeach President Robert Mugabe - the man who has dominated politics in the country for more than four decades, first as a guerrilla leader and then as ruler.

The historic parliamentary session in Zimbabwe is expected to start with a motion, laying out the charges against President Robert Mugabe and his wife Grace Mugabe.

On Monday, Zanu-PF member of parliament Paul Mangwana said:

Image source, AFP

If - as is likely - the motion is approved by a 50% majority in a joint sitting of the National Assembly and the Senate, a committee from both chambers will be appointed to investigate.

Should the committee support the charges, the president can then be removed if both houses back them with two-thirds majorities.

Mr Mangwana said the process could be fast-tracked and completed by Wednesday, "because the charges are so clear". But others insist the process could take longer.

Zimbabwean lawmakers have gathered in parliament to start impeachment proceedings against President Robert Mugabe.

A news site which monitors the legislature's activities has shared this picture of the scene inside parliament:

Image source, AFP

Zimbabwe's President Robert Mugabe has been in power since independence in 1980. He has won elections, but over the past 15 years these have been marred by violence against political opponents.

Above all, Mr Mugabe has presided over a deepening economic crisis. Zimbabweans are on average 15% poorer now than they were in 1980.

What triggered moves to oust him was the dismissal of his former comrade, Emmerson Mnangagwa, as vice-president two weeks ago.

The move was seen by many as clearing the way for Mr Mugabe's wife Grace to succeed her husband as leader.

The move riled top soldiers, who stepped in and put Mr Mugabe under house arrest. However he remains president, and in recent days has defied calls from his own party and from protesters to stand down.

In a further sign of his dwindling authority, only a handful of his ministers turned up for a cabinet meeting on Tuesday.

Read: The army chief who took away Mugabe's power

Rallies and prayers are being held in Zimbabwe's capital, Harare, ahead of the move by MPs in parliament to begin impeachment proceedings against President Robert Mugabe, as these tweets show:

Image source, Getty Images

Botswana's President Ian Khama has written an open letter to his Zimbabwean counterpart, Robert Mugabe, calling on him to resign.

Noting that he was breaching "the normal method of communication between leaders", Mr Khama said Mr Mugabe, 93, should listen to the wishes of his people and "do the honourable thing by voluntarily relinquishing power".

He adds:

Image source, AFP

Zimbabwe's Parliament is due to convene within the next 30 minutes to begin impeachment proceedings against President Robert Mugabe.

Impeachment is the ultimate humiliation for a president. Lawmakers act as jurors, convicting him of various offences.

In the 93-year-old's case, he is accused of being "incapacitated", and of allowing his 53-year-old wife, Grace Mugabe, to usurp his presidential powers.

Usually, when the ruling party - or parliament - want to remove a president, they go for the less humiliating option of passing a no-confidence vote in him.

But Mr Mugabe's opponents - who have rallied behind his sacked deputy, Emmerson Mnangagwa - have decided to go for the kill.

Stay with us as we cover all the drama.

The Reuters news agency is reporting that five ministers and the attorney general showed up for the cabinet meeting called by President Robert Mugabe.

The other 17 attended a meeting to discuss Mr Mugabe's impeachment, it reports:

"All cabinet ministers" in Zimbabwe refused to attend a meeting called by President Robert Mugabe this morning, the leader of the War Veterans Association, Chris Mutsvangwa, has said.

This was the first cabinet meeting Mr Mugabe tried to convene since last Wednesday's army takeover.

Speaking at a press conference in the capital, Harare, Mr Mutsvangwa, called on regional leaders, who are meeting in Angola, to urge Mr Mugabe to resign.

Image source, AFP

Zimbabwe's state-run daily newspaper has posted a video of people celebrating in the capital, Harare, ahead of the historic parliamentary session to impeach President Robert Mugabe, once hailed as a great African revolutionary:

The daughter of the man widely tipped to be Zimbabwe's next president, Emmerson Mnangagwa, has been speaking to the BBC's Newshour programme.

Farai says her father, nicknamed"crocodile", is "dedicated" and "pushes his children to do the best they can".

Listen to her full comments:

Profile: Emmerson Mnangagwa: The 'crocodile' who snapped back

MPs from Zimbabwe's ruling Zanu-PF are said to have unanimously agreed to impeach President Robert Mugabe following a meeting at their party headquarters in the capital, Harare, a journalist has tweeted:

Image source, Reuters

Veritas, a non-governmental organisation which provides legal services to Zimbabweans, has outlined how a president is impeached:

"Under section 97 of the Constitution impeachment is a three-stage process:

1. First, the Senate and the National Assembly must meet in a joint sitting and resolve, by a simple majority of their total membership, that the president should be removed from office on any one or more of four grounds:

a. serious misconduct

b. failure to obey, uphold or defend the Constitution

c. wilful violation of the Constitution

d. inability to perform his duties because of physical or mental incapacity.

[Note: An arguable case could be made for charging President Mugabe with all four grounds]

2. Once a resolution has been passed, Parliament’s Committee on Standing Rules and Orders must appoint a nine-member committee of Senators and members of the National Assembly to investigate the removal of the President.

Although section 97 of the Constitution does not say so, the committee would have to give the President a full opportunity to respond to the allegations against him – he has a right to a fair hearing under section 69 of the Constitution.

3. If the committee recommends that the President should be removed from office, the Senate and National Assembly must meet, again in joint session, to deliberate the recommendation, and if in that joint session they resolve by a two-thirds majority of their total membership to adopt the recommendation then the President immediately ceases to hold office.

Image source, Re

Impeachment is an elaborate process and would take time to complete. How long is difficult to say, because Parliament’s Standing Orders do not specify what notice must be given of impeachment motions, nor how joint sittings of the two Houses are convened - in fact they do not deal with impeachment at all.

In the absence of a laid-down procedure, presumably the Committee on Standing Rules and Orders, the Speaker and the staff of Parliament will make it up as they go along. Nonetheless the process would need at least several days to complete bearing in mind that:

An impeachment motion, like all motions, requires at least a day’s notice to be given before it is debated [perhaps Parliament would waive this requirement].

· Detailed grounds of impeachment would have to be prepared.

· A joint sitting would have to be arranged

· An investigation committee would have to be appointed.

· The committee would have to investigate the grounds of impeachment and give the President an opportunity to state his case [and the President would have no incentive to be brief] and to prepare a report to Parliament.

· Another the joint session would have to be convened to consider and vote on the committee’s report.

Image source, AFP

Result of Impeachment

If President Mugabe leaves office through impeachment, a Vice-President takes over as Acting President [paragraph 14(4) of the Sixth Schedule to the Constitution]. All the Ministers who were appointed by him will stay in office, and so will the one remaining Vice-President, Mr Mphoko.

The fact that he may be outside the country, or in detention, or stripped of his party position and membership does not alter his status as Vice-President.

If Vice-President Mphoko were to resign then there would be no Vice-President, and only a President can appoint another Vice-President.

If there were no Vice-President to act as President, the remaining Cabinet Ministers would have to appoint one of themselves as Acting President in terms of section 100(1)(c) of the Constitution.

Such an Acting President could appoint a Vice-President, but only with the approval of a majority of the Cabinet.

A much simpler option would be if Mr Mugabe were to retire and appoint a new Vice-President before doing so."