People have already arrived to queue for the Queen’s lying in state in London – two days before the line opens.
Infrastructure is being set up and security staff are preparing for millions of people to wait to pay their respects to the late monarch, whose coffin will be placed in Westminster Hall from 5pm on Wednesday until the morning of September 19.
Full details will be released at 10pm on Tuesday.
Ms Nathakumaran, who is staying at a hotel in Lambeth so she does not miss the opportunity to pay her respects, told the PA news agency she began “admiring the royal family” from the age of 10 and has “a huge respect for them”.
The administrative assistant, who grew up in Sri Lanka before moving to the UK to study in the 1980s, said she is going to call her daughters to change her bag and bring warmer clothes and glucose bars to keep her energy up.
On why she wants to see the Queen lying in state, she said: “Because she has done a good service. She was very devoted. She has done a service to our country, Britain and also international and the Commonwealth.
“I do respect her way of kindness, how she treats everyone equal, the religions and the communities. She sees everyone as equal.”
On why she arrived so early, she said: “I really, really want to be part of it.
“I don’t want to miss it in case… they said they are probably going to control the crowds if (the queue) gets too long.”
She said the Queen died on the seven-month anniversary or her husband’s death in February, describing it as “a personal connection to our family”.
Anne, 65, from Cardiff, who wished not to give her last name, was the second person to join the queue.
She arrived at about 2:15pm with a chair and a Welsh flag, saying she had got up at 3am and travelled with a group from Cardiff but only found out where to go after seeing Ms Nanthakumaran on the news.
She said: “So here we are and representing Wales.”
On hearing the news of the Queen’s death, she said: “I couldn’t stop crying for days.”
Anne said waiting for days is “nothing to me” adding that she had come prepared with Welsh cakes and a sandwich as well as ordering from Deliveroo.
Grace Gothard, from Mitcham in south London, was the third person to join the queue.
Ms Gothard, originally from Ghana, had a Union flag draped around her neck and was carrying a cardboard cut-out of the Queen and some marmalade.
She had no tent, sleeping bag or coat.
She told reporters: “The Queen was everyone’s mother, she protected the Commonwealth and made sure everyone is protected.
“I’ve been to royal events in the past, weddings and funerals, and I was so upset when I found out about this, so I wanted to see her coffin.
“I think Charles will be a good king, he has his mother’s traits.”
Security staff and stewards are lined up at regular intervals along the expected queue route, which is understood to stretch from Victoria Tower Gardens across Lambeth Bridge down to Westminster Bridge before veering right then left down Belvedere Road, through Jubilee Gardens back to South Bank and along to the Tate.
Metropolitan Police officers, as well as Welsh police officers, are manning the expected route, parts of which are already lined with barriers.
After the Tate, it is unclear where it will flow from there, security staff say.
Portaloos and crowd control infrastructure such as barriers and temporary flooring have been set up inside Victoria Tower Gardens, which is likely to be the pinnacle of the queue before it leads into Cornwall Gardens.
A marquee and armed police could be seen at the entrance to Cornwall Gardens, with several police and emergency service vehicles parked across the road.
Security staff by Victoria Tower Gardens said crowds are expected to swell ahead of Wednesday afternoon.
They said the queue is likely to snake for miles, potentially all the way along the river to Tower Bridge.
People will not be allowed to camp and will be given numbered wristbands to indicate their place in the queue so they are able to leave and come back, security staff said.