The House of Commons is going to pay tribute to Sir David Amess today.
A morning of prayers will be followed by a minute's silence this afternoon - and politicians will be able to share their memories of the Conservative MP.
Most of the planned timetable for the day is going to be rescheduled.
Sir David died after being stabbed during a constituency surgery he was holding in Leigh-on-Sea, Essex, on Friday.
A memorial service is due to take place at Westminster Abbey from 6pm, but limited space means it will only be open to MPs and peers.
Meanwhile, a book of condolence is being placed in the House of Commons Library, as well as in Westminster Hall and Portcullis House.
On Sunday evening, Sir David's family said their "hearts are shattered" by what has happened, and described his death as "cruel and violent".
In a statement, his wife, four daughters and son said: "Strong and courageous is an appropriate way to describe David. He was a patriot and a man of peace.
"So we ask people to set aside their differences and show kindness and love to all. This is the only way forward. Set aside hatred and work towards togetherness.
"Whatever one's race, religious or political beliefs, be tolerant and try to understand.
"As a family, we are trying to understand why this awful thing has occurred. Nobody should die in this way. Nobody."
Police arrested a 25-year-old man at the scene of Sir David's death on suspicion of his murder, understood by Sky News to be named Ali Harbi Ali, and officers have been granted a warrant to detain him until 22 October.
He is the son of a former senior Somali government official, Sky News understands.
A spokesperson at the Somali Embassy in China has also confirmed that the terror suspect is the nephew of Somalia's ambassador to China, Awale Kullane.
Officers have been searching properties in London linked to the counter-terrorism investigation, and have been seen carrying bags of what appears to be evidence from the addresses.
Earlier on Sunday, Home Secretary Priti Patel suggested to Sky News that MPs could get police protection during their constituency surgeries in the wake of the attack, after it sparked a debate about their safety.
Commons Speaker Sir Lindsay Hoyle has also said there will need to be a discussion in the coming days around MPs' security, and any measures that should be taken.
Sir David, who was 69 years old and a father-of-five, had been an MP for almost 40 years.
His family have urged the public to support his causes, including a campaign to make Southend-on-Sea a city.