The Queen stripped Zimbabwean President Robert Mugabe of his honorary knighthood on Wednesday.

Acting on the advice of British Foreign Secretary David Miliband, the Queen's move is meant to show displeasure over alleged human rights abuses by the Mugabe administration.

According to Miliband, Mugabe should be stripped of the honour because Zimbabwe's opposition party has suffered violence and intimidation by the government ahead of Friday's presidential run-off vote.

U.S. President George Bush and former South Africa president Nelson Mandela also gave Mugabe strong rebukes Wednesday.

Bush said the runoff vote set for Friday will not have a legitimate outcome.

"Friday's elections appear to be a sham," he said. "You can't have free elections when a candidate is not allowed to campaign without fear of intimidation."

Nelson said Zimbabwe is suffering from a "tragic failure of leadership." It was the first time he had publicly commented on the current crisis facing the country.

A campaign of violence against Mugabe's political foes has forced opposition leader Morgan Tsvangirai to take refuge at the Dutch embassy in Harare. He emerged briefly to call on African leaders to help guide talks to end the crisis in Zimbabwe.

Tsvangirai, who is with some 300 of his supporters at the embassy, said talks cannot begin until there's an end to attacks on his supporters.

In another development, Zimbabwe's electoral commission said the decision of Tsvangirai to not participate in Friday's runoff vote means nothing legally.

"Accordingly, the commission does not recognize the purported withdrawal. We are, therefore, proceeding with the presidential election run-off this Friday as planned," Zimbabwe Electoral Commission chairman George Chiweshe said Wednesday.

Tsvangirai said at a news conference at his Harare home that his Movement for Democratic Change party won't negotiate with Mugabe if Friday's run-off vote goes ahead.

"The issue is that we will not have anything to do with a post-(June) 27 government arising out of this so-called election," he said.

"We have said we are prepared to negotiate on this side of the 27th, not the other side of the 27th."

He called for help from the African Union and United Nations to manage a "transitional process."

Tsvangirai -- who won the March 29 vote, but not by a clear majority -- had taken refuge in the Dutch embassy after announcing Sunday he wouldn't participate in the run-off.

Outside help

Human rights activist Stephen Lewis said strong action needs to be taken against the Mugabe administration, but military intervention seems unlikely.

"It's clear, I think, that the United Nations isn't prepared to take military action," he told CTV Newsnet. "Any further economic boycott doesn't mean a great deal because the country is already devastated, and Mugabe is writing off any admonitions from the United States and United Kingdom as coming from imperial powers.

"What will change the future of Zimbabwe is what the southern African countries do."

However, he said the current leader of South Africa, Thabo Mbeki, has failed to take a strong enough stance against Mugabe. Mbeki has suggested Mugabe form a coalition government with the opposition party.

"Mbeki's behaviour is inexplicable," said Lewis.

The African National Congress, the ruling party of South Africa, issued a statement calling on Mugabe to stop "riding roughshod" over the opposition. However, it also warned against direct international intervention.

"A lasting solution has to be led by the Zimbabweans and any attempts by outside players to impose regime change will merely deepen the crisis," the ANC said.

The party also criticized Britain for not following through on its pledges to help fund efforts to help black Zimbabweans obtain farmland.

Britain has expressed concerns about corruption sapping the effectiveness of such a program.

On Tuesday, Mugabe -- president since the country won independence from Britain in 1980 -- vowed he wouldn't back down in the face of international pressure.

"We will proceed with our election, the verdict is our verdict. Other people can say what they want, but the elections are ours. We are a sovereign state, and that is it," Mugabe said.

"Those who will want to recognize us on the basis of objectivity will do so. Those who don't, keep your judgment to yourselves. Our people are going to vote, and that vote will decide whether we have won or lost."

"They can shout as loud as they like from Washington or from London, or from any other quarter. Our people, only our people, will decide, and no one else," the Zimbabwean leader said.

On Tsvangirai's decision to seek refuge, the 84-year-old said: "(He) is frightened of the people. He ran and sought refuge in the Dutch Embassy .... Seeking refuge from what? Nobody wants to harm him."

Tsvangirai claims 86 of his supporters have died and another 200,000 have been displaced by political violence.

With files from The Associated Press