Entry to the queue to see the Queen lying in state has been paused for at least six hours after it hit capacity.
The queue currently has a wait time of 14 hours and is 4.9 miles long - stretching back to Southwark Park.
"Southwark Park has reached capacity," the Department for Culture, Media and Sport (DCMS) said. "Entry will be paused for at least 6 hours. We are sorry for any inconvenience.
"Please do not attempt to join the queue until it re-opens."
The entrance to Southwark Park was closed to stop more people from joining both the main queue and an overspill queue.
The DCMS also said the accessible queue had reached capacity and entry for allocation of wristbands was currently paused.
"Those with wristbands and entry times will still be able to view the Lying-in-State," it said.
"Please do not attempt to join until it resumes."
For most of the night the line was nearly five miles long, with Southwark listed as the nearest landmark.
Firefighters gave out bottles of water along the route while volunteers from the Samaritans were available and stewards, police and portable toilets lined the route.
Mourners spoke of "breath-taking" serenity in Westminster Hall where "you could hear a pin drop".
PhD student Fiona Holloran wept after paying her respects.
The 34-year-old Londoner said: "It was very moving to see the vigil around her - I was a little bit surprised at how much it struck me."
She had queued with her baby strapped to her in a carrier but said the wait had been "worth it".
"It's lovely that everyone has just a moment to themselves - no one was pushing," she added.
Amy Harris, 34, said the atmosphere in Westminster Hall was "breath-taking".
"When you're able to go in and have a moment to look at it and reflect, the serenity of it - to be able to pay your respects in such a serene place, it's very peaceful," she said.