Tens of thousands of people are set to say a final farewell to boxing legend Muhammad Ali in his home city of Louisville in Kentucky.

The heavyweight champion and rights activist died last Friday aged 74.

A procession will take Ali’s body past key sites in his life, ahead of an interfaith memorial service.

Actor Will Smith and ex-boxer Lennox Lewis will be among the pallbearers, while former President Bill Clinton will deliver one of the eulogies.

Tens of thousands are expected to line the streets for the procession, while free tickets for the 18,000-strong memorial service, taking place at a major sports centre, were snapped up within half an hour.

The motorcade procession was due to begin at about 09:30 local time (13:30 GMT) and take the coffin past his childhood home, the Ali Center, the Center for African American Heritage and then down Muhammad Ali Boulevard.

The procession, expected to take about 90 minutes, will end at the Cave Hill Cemetery where Ali will be laid to rest in a private ceremony.

The funeral service at the KFC Yum! Centre will begin at 14:00 local time.

Comedian Billy Crystal will also deliver a eulogy, while sports journalist Bryant Gumbel, the daughter of civil rights activist Malcolm X, Attallah Shabazz, and Ali’s wife, Lonnie, and daughters, Maryum and Rasheda, are also expected to speak.

Among those expected to attend the service is King Abdullah of Jordan.

Turkish President Recep Tayyip Erdogan attended Thursday’s prayer ceremony and had been due at the service, but reports say he has cut short his visit to the US.

The reasons for his departure are not clear, though there are reports of differences with the funeral’s organisers.

President Barack Obama will not be there, as he is to attend his eldest daughter Malia’s graduation.

But in a video message, he said: “This week we lost an icon. A person who for African Americans, I think, liberated their minds in recognising that they could be proud of who they were.”

White House senior adviser Valerie Jarrett – who knew Ali – will represent the president.

Lennox Lewis, a former world heavyweight boxing champion himself, said it was an honour to be a pallbearer and that Ali’s memory would never fade.

“The term ‘float like a butterfly, sting like a bee’ will always be remembered. He is an icon and a legend of boxing,” he said.

The other pallbearers are family and friends, along with Will Smith, who portrayed Ali in the 2001 film about the boxer’s life.

Abi Ajram, 48, who has made a 4,000-mile trip from London to pay his respects, told PA: “I feel Muhammad Ali deserved the world turning up for him. He was the number one.”

The funeral service will be streamed live online.

One sour note was the report that some people were trying to sell the free tickets to the service on the internet.

Ali family spokesman Bob Gunnell said he was “personally disgusted” at attempts to profit from the event.