South African Nobel peace laureate Desmond Tutu has lashed out at his government for "kowtowing" to China by barring the Dalai Lama from attending a global summit of fellow prize winners in Cape Town.

Breaking his silence as the World Summit of Nobel Peace Laureates appeared to be on the point of collapse, Mr Tutu said he was "ashamed to call this lickspittle bunch my government".

South Africa denied Tibet's exiled spiritual leader permission to attend the summit to avoid angering China, which regards the Buddhist monk as a campaigner for Tibetan independence.

The summit, to be held in mid-October, was meant to celebrate the 20th anniversary of the end of apartheid and the legacy of the late president and Nobel peace prize winner, Nelson Mandela.

Mr Tutu said the move sullies the memory of Mr Mandela, who would not bend to the will of powerful states in his time as president.

"When the Americans told [Mandela] he couldn't continue his friendship with presidents Gaddafi and Castro, he told them to go and jump in the lake," Mr Tutu said.

Mr Mandela's heirs in the ruling African National Congress party under president Jacob Zuma had now "spat in [Mandela's] face", Mr Tutu said in a statement.

He spoke out after fellow laureate, American Jody Williams, claimed the summit had been cancelled because of the Dalai Lama row.

The Dalai Lama greets the audience before his conference in Mexico City, October 12, 2013. ( Reuters: Edgard Garrido )

"The summit has been cancelled because enough Nobel laureates refused to go," Williams said in the northern Indian town of Dharamsala, where the Dalai Lama is based.

But there was no immediate confirmation of the cancellation of the summit from the organisers in Rome.

The mayor of Cape Town said an announcement on the summit would be made today.

Mr Tutu's daughter, Mpho, said her father had remained silent over the visa issue because after a previous unsuccessful run-in with the government over the same issue, he believed others might have more success.

"When His Holiness was prevented by our government from attending my 80th birthday [in 2011] I condemned that kowtowing to the Chinese roundly and reminded the ANC government that it did not represent me," Mr Tutu said.

"I warned them then that just as we had prayed for the downfall of the apartheid government so we would pray for the demise of a government that could be so spineless.

"The Nobel Summit in Cape Town, the first to be held on our continent, was meant to celebrate Madiba. His own comrades have spat in his face, refusing to see him honoured by the holders of the blue ribbon of awards and honours."

AFP