Traditionally gentlemanly affairs, the Commonwealth Heads of Government Meeting (CHOGM) is held once every two years to give the leaders a chance to talk candidly behind closed doors about the problems of the world.

But the suspension of President Robert Mugabe's Zimbabwe from the body's council 20 months ago, after he was re-elected in a poll marred by violence and fraud, has triggered deep divisions that threaten to overshadow proceedings.

In the build-up to this year's meet in the Nigeria, the split has taken on the appearance of a quasi-racial divide between the former British colonies in Africa, and the "white Commonwealth" of Britain, Australia and New Zealand.

Some African leaders, most publicly South Africa's President Thabo Mbeki, have lobbied for Mugabe to be brought back into the fold, while Australia's Prime Minister John Howard wants Zimbabwe permanently expelled.

The summit's Nigerian host, President Olusegun Obasanjo, came under pressure from both sides in the row and made a last-minute visit to Harare before deciding late in the day not to invite Zimbabwe.

The row, fuelled by high-octane anti-Western rhetoric from Mugabe himself, has at times appeared capable of splitting the Commonwealth.

But on Wednesday the body's Kiwi secretary general, Don McKinnon, played down the racial angle and said the dispute transcended the north-south divide.

Asked whether, as Mugabe claimed, there was a white alliance out to get at Zimbabwe, he told reporters: "I do reject that.

"I've talked to just about every Commonwealth leader more than once over the past six months. There's variety of views over how to deal with Mugabe, there's by no means a split between Africa and the rest of the world."

He also said that the meeting could produce a "very strong statement" that could help reconcile the rich and poor worlds on another issue -- trade -- ahead of the next round of WTO talks, which have stalled.

McKinnon himself could, however, fall victim to the argument.