Retired archbishop Desmond Tutu, one of the most prominent figures in the struggle against apartheid in South Africa, has been excluded from the funeral of Nelson Mandela on Sunday in what has been described as a politically motivated snub.

Critics accused the governing African National Congress (ANC) of looking petty by apparently failing to invite Tutu, one of the most vocal campaigners for Mandela's release from jail during white minority rule.

An estimated 5,000 guests including Prince Charles, Malawian president Joyce Banda and various other dignitaries will attend the state funeral in Qunu, the village where Mandela grew up in Eastern Cape province. Tutu's daughter Mpho, chief executive of the Desmond & Leah Tutu Legacy Foundation, said on Friday: "The archbishop is not an accredited clergyperson for the event and will thus not be attending." His office declined to comment further.

Against this backdrop of dispute, Mandela's body arrived in the early hours of Saturday at Waterkloof air base for a farewell ceremony held by the African National Congress ahead of being flown on Saturday afternoon to the Eastern Cape.

Tutu has become a fierce critic of the ANC in recent years. In 2011 he compared it unfavourably to the apartheid regime and warned that "one day we will pray for the defeat of the ANC government".

Eyebrows were raised when Tutu's name did not appear on the order of service for Mandela's national memorial service in Johannesburg on Tuesday. He was eventually invited to speak after the main programme, but by then the stadium was virtually empty.

His absence from Sunday's burial, the climax of an unprecedented week of mourning in South Africa, provoked anger and bewilderment. Bantu Holomisa, a former ANC politician close to the Mandela family, said: "There must be a mistake. Why would the government not do that? He should be the first person accredited. It's strange – there must have been a breakdown."

Asked if Tutu's attacks on the ANC were the cause, Holomisa replied: "They cannot use that. Mandela and Tutu were like brothers. Mandela had time for Tutu and Tutu had time for Mandela. It doesn't sound good at all." Aubrey Matshiqi, a research fellow at the Helen Suzman Foundation, said: "It's quite sad that he's not been invited. Is it the family or is it the government? Is it both? Did the family come under pressure not to invite him?

"It's a very bad decision, given how close they were. In the absence of a convincing explanation, it looks petty."

Allister Sparks, a veteran journalist and biographer of Tutu, said: "I don't know what to make of it. I would have thought he belonged there. Tutu has been quite a vocal critic of the ANC. It comes as a surprise and arouses suspicions of a political motivation behind it."

Reflecting on Tutu's relationship with Mandela, Sparks added: "They were very close. Through the period when Mandela was in jail, Tutu was effectively the leader of the liberation struggle in this country."

Earlier this year Tutu condemned the Mandela family for fighting each other in court while Mandela lay ill in hospital, describing their public battle over his children's reburial place as "almost like spitting in Madiba's face".

A spokesman for the Mandelas said: "The family is not involved in who should come and not come at that level. They are busy mourning. It is the state that is encouraging people to attend or not attend. I'm not aware of any exclusion."

Government ministers in Qunu on Friday were reluctant to comment on the matter. Dipuo Peters, the transport minister, said: "In African culture we don't invite people to funerals; they say they would like to attend. I don't know about Bishop Tutu - you're giving me news."

ANC spokespeople did not respond to requests for comment.

The South African government also faced further embarrassment over reports that a sign language interpreter who gesticulated nonsense during Mandela's memorial service once faced a murder charge. A spokesman said officials were examining how Thamsanqa Jantjie was selected to interpret at the event, during which he stood close to Barack Obama and other leaders. The South African television channel eNCA reported on Friday that court records showed he had previously been charged with murder, rape, kidnapping, theft and other charges, although many of the charges were subsequently dropped on the grounds that he was mentally unfit to stand trial.

Mandela's last journey will bring sections of Eastern Cape province to a standstill. Commercial flights will be redirected to cities further south and his coffin was expected in the provincial city of Mtatha at nine o'clock on Saturday morning.Roads will then be closed for the funeral cortege, which includes a phalanx of outriders and more than a dozen armoured personnel carriers, to make the short drive to Qunu ahead of his burial on Sunday morning.

Preparations for the three-hour funeral have overwhelmed the sleepy village where pigs, goats, sheep and cattle roam around among single story roundhouses. A giant marquee that resembles an early 20th century airship has been erected on Mandela family land to receive guests expects to include dozens of heads of state as well as Prince Charles, Bill Clinton and civil rights activist Rev. Jesse Jackson.