Opposition activists say they are becoming more hopeful that all this intimidation might in fact backfire, they now think there is a real chance that it might encourage many ordinary people to vote against the president

But diplomats did not seem impressed. They pointed out that President Mugabe had made vague promises like that before. What they want now is concrete action to approve monitors who are already being lined up to start going in this Sunday.

It was left to Jack Straw, Britain's foreign secretary, to announce what the EU intended.

"My message is that the European Union means business, " he said. "We want to see Zimbabwe operate free and fair elections, or the leadership - not the people - will pay the penalty."

He added that expectations were not high, so that is why it had been made clear that sanctions would follow.

Opposition hopes

There is a particular reason to give Mr Mugabe this one more chance, to calibrate the EU response so carefully: what is happening on the ground in Zimbabwe.

Farms are no longer the only targets of violence

In the past few weeks there have been reports of increasing violence from Mr Mugabe's militias against suspected supporters of the main opposition party, the Movement for Democratic Change (MDC).

No longer is the violence and intimidation just about the appropriation of formerly white farmland. Opposition headquarters have been firebombed, some candidates attacked, some even killed, and in some areas systematic campaigns have been reported to confiscate voting cards from some people.

But western diplomats have noted that the opposition now seems more optimistic.

Activists say they are becoming more hopeful that all this intimidation might in fact backfire. They now think there is a real chance that it might encourage many ordinary people to vote against the president.

The opposition has not forgotten that it did better than expected in the earlier parliamentary elections. Opposition leaders think they can still win these elections - but only if the outside world is there to keep an eye on things.

Rigging fears

But in Brussels those lobbying for Zimbabwe's opposition are wary.

The opposition's hopes rest on a meaningful international presence

Grace Kwinjeh is the MDC's representative In Brussels. She agrees there is a chance people will use the upcoming election to register discontent with the president, but only if they are confident it will not be rigged.

And that means not just getting proper election monitors in - they must have a clear mandate, with access to polling stations, to opposition as well as government campaigners and a real ability to monitor the situation.

Otherwise the international presence will simply lend credence to a process that does not deserve it.

But what if Mr Mugabe refuses to comply?

In one way what the EU decision boils down to is that the threat of sanctions often proves more effective than sanctions themselves.

Feeble response?

What British and other European diplomats fear is that once sanctions are imposed and Mr Mugabe decides the international door has been shut in his face, he will have no incentive to co-operate.

We don't think he'll let international observers in and let the elections be free and fair; time is running out and quiet diplomacy has been tried, and basically it has not worked

ICG Africa programme co-director Fabienne Hara

Then how will the outside world persuade him to allow international observers in to monitor the election?

One organisation based in Brussels thinks all this new pressure now may be coming too late.

The International Crisis Group (ICG) in one of its latest reports dismissed the international response to Zimbabwe so far as all bark and no bite.

Its conclusion is that sanctions should be imposed without delay, and in fact should have been imposed months ago if they were to have any real impact on March's elections.

"We don't think he'll let international observers in and let the elections be free and fair," says the ICG's Africa programme co-director Fabienne Hara. "Time is running out, and quiet diplomacy has been tried, and basically it has not worked."

US and Commonwealth roles

There are still other international pressure points to bring to bear.

The US Congress has already approved a bill that would allow the US president to impose targeted sanctions, echoing those being threatened by Europe.

But perhaps most important are the symbolic steps the Commonwealth could take. The eight foreign ministers of their Ministerial Action Group meet in London on Wednesday.

Britain is also part of that grouping and has already said it will recommend calling for Zimbabwe's suspension from the Commonwealth for what UK Prime Minister Tony Blair last week in the British parliament called President Mugabe's "disgraceful" actions.

Whether the African foreign ministers at the meeting will agree is still uncertain. Until now, many of them have argued quiet diplomacy would be more effective.

But concern about the violence that might overshadow these elections is considerable. Many will be watching Wednesday's meeting closely.