Members of the Royal Family and the prime minister will join families of victims of the Grenfell Tower fire for a memorial at St Paul’s Cathedral.
About 1,500 people are invited to the multi-faith service, including the bereaved, survivors and rescue workers.
Joining them are the Prince of Wales, Duchess of Cornwall, Duke and Duchess of Cambridge and Prince Harry.
The service, beginning at 11:00 GMT, will remember 71 people who died in the 14 June fire.
It will also give thanks to everyone who assisted on the ground at the time of the tragedy and since – including the emergency services, the recovery team, the community, public support workers and volunteers.
The final death toll from the fire was put at 53 adults and 18 children, including stillborn baby Logan Gomes, following an arduous process of recovering and identifying remains from the block.
One of those in attendance will be Tiago Alves, who escaped the blaze with his family.
He told BBC Breakfast his thoughts would be with bereaved families during the memorial: “Today is a day not about survivors; today is purely about the bereaved, their families and the loved ones they have lost.”
He said the memorial was going to be “quite emotional” and would bring back a lot of awful memories for many people.
But he added: “The reason we are doing this today is so that people never forget – we want people to remember.”
A banner with the Grenfell Heart will be displayed, while there will be performances from the Ebony Steel Band, Portobello Road Salvation Army Band, an Islamic girls’ choir from the Al Sadiq and Al Zahra Schools, and St Paul’s Cathedral Choir.
A pre-recorded sound montage of anonymous voices from the Grenfell community will also be played.
At the end of the service, which will also be attended by Theresa May and Labour leader Jeremy Corbyn, bereaved families and survivors will leave the cathedral in silence, holding white roses.
Clarrie Mendy, whose cousin Mary Mendy and her daughter Khadija Saye died in the fire, is one of those who helped organise the memorial event, which will be broadcast live on BBC One.
“I just hope this service resonates with people, with the hunger people have spiritually,” she said.