Police have removed protesters from Oxford Street, Waterloo Bridge and Parliament Square, but some activists remain in the trees and at Marble Arch.
The group said it would march to Parliament on Tuesday morning to deliver letters inviting MPs to a Citizens’ Assembly on the climate and ecological crisis.
“Extinction Rebellion activists remain in occupation of Parliament Square trees,” the group said in a statement.
“The brave activists have lived in the trees for eight days even as the rest of the square was cleared, to highlight government inaction on global extinction and climate emergency.
JOIN US TOMORROW MORNING: we will march to Parliament to deliver letters inviting MPs to a Citizens’ Assembly on the climate and ecological crisis. Meet: 9:30am, under Marble Arch. #ExtinctionRebellion— Extinction Rebellion 🐝⌛️🦋 (@ExtinctionR)April 22, 2019
“We have several a climbers living in the trees in Parliament Square to make clear our commitment and the risks we are prepared to take to ensure that we have a future.”
They added that “all they’ve had was silence” from Prime Minister Theresa May.
One of the climbers, who gave his name is Dav — Direct Action Volunteer — held up a t-shirt emblazoned with the phrase “Public Nuisance”. Speaking from his hammock, the activist, 39, told the Standard that despite intricate harnesses — with ropes spanning to trees across the street — it was “definitely death” if one of them fell.
He said he was planning to stay in the trees “at least a few days”, and hinted activists had prepared for attempts to bring them down with “hardware to make it difficult”.
He added: “It will be a spectacular eviction as and when they do come up.”
About 9,000 police officers have been responding to the protest since it began a week ago on 15 April.
A total of 1,065 people have been arrested and 53 have been charged for various offences including breach of Section 14 Notice of the Public Order Act 1986, obstructing a highway and obstructing police.
Scotland Yard have warned officers will be “robust” against activists staging demonstrations on Tuesday.
In a statement, the Metropolitan Police said there will be conditions imposed “on all planning to attend”.
Any protest must take place within an area permitted by police and demonstrations must be finished by the end of the day.
The statement read: “Any organiser or person taking part in the protest failing to comply with these conditions or inciting others not to comply with them will be committing an offence and will be liable to arrest.
“The decision to impose the above conditions has been taken based on the information and intelligence available to the Met at this time meaning that that Met feels this action is necessary in order to prevent the demonstrations from causing serious disruption to the community.
“A robust policing plan will be in place for the demonstration tomorrow.”
Mayor of London Sadiq Khan said the protest was taking "a real toll" on London's police and businesses.
"I'm extremely concerned about the impact the protests are having on our ability to tackle issues like violent crime if they continue any longer," he said.
On Sunday, teenage activist Greta Thunberg told the rally in Marble Arch that they were "making a difference".
The 16-year-old, told the crowd "humanity is standing at a crossroads" and that protesters "will never stop fighting for this planet".
For more than a week the activists have stopped traffic in a series of demonstrations including fixing a boat at the junction of Oxford Street and Regent Street, occupying Waterloo Bridge and disrupting the Docklands Light Railway by climbing on a train.