Former Guardian newspaper correspondent in Zimbabwe Andrew Meldrum tells the BBC his views on the opposition protests called for this week.
The first thing that is beyond doubt is that the national strike, the stayaway from work, will be effective for the four-five days and will close the country down.
The Movement for Democratic Change has already proved twice in the past two months that it has the force with the people to be able to make those strikes effective.
Mugabe has no intention of going quietly
Getting people out on the streets when the police and the army are showing such overwhelming force is another question.
Some people are expecting a kind of overwhelming show of people. Let us say hundreds of thousands of people that would surround the seat of government and force a toppling of government - something like what happened to Milosevic in Yugoslavia.
I don't believe that is what is going to happen. I think it may be smaller groups of people in the various townships around Harare and maybe a small group in the city centre. But even that will be enough to shake the foundations of the government.
Can we take it for granted that the security authorities' response will be, shall we say, robust?
Very robust - and there are already tanks and armoured personnel carriers in the townships outside of Harare.
There are armed roadblocks ringing the city and in other major cities in Zimbabwe the police and the party itself has warned that it is going to deal forcefully with those and teach them a lesson. So, yes, I think there is a very real danger of a strong measure of force.
We have seen plenty of strikes before, we have seen plenty of demonstrations before as well, what sets this week apart?
Both of the national strikes that happened in the past couple of months rattled the government a great deal. This strike is going to do the same thing.
But also the public demonstrations are going to weaken the view of Mr Mugabe amongst his African allies, from South Africa to Nigeria.
They are going to see that the majority of the people are not only against the government, many people are willing to come out in a show of force against the government.
And that is going to weaken the perception of Mugabe.
He is already being pressed by fellow African leaders, by the Commonwealth as well as of course by the EU and Britain and the US.
This is going to weaken the perception of Mr Mugabe as a man of power.
So, Mr Tsvangirai is saying that the political landscape will never be the same again. You are effectively saying the same thing. A week from now what is that landscape going to be looking like?
I think it is going to be much more difficulty for Mr Mugabe to avoid having negotiations with the opposition party and it is going to be much more difficulty for him to say that a transition period leading to free and fair elections is out of the question.
It is certainly going to be impossible for Mr Mugabe to set preconditions for these negotiations. In other words time is running out for him.
He has an opportunity to negotiate his exit at this point but pretty soon I think that that he will lose control of even that.