Participants will peacefully break the law in order to stop the tube and then will wait to be arrested.
Campaigners are planning to disrupt London Underground tube services as part of a series of climate change protests which have led to nearly 300 people being arrested in the capital.
Extinction Rebellion demonstrations have been taking place at Parliament Square, Waterloo Bridge, Oxford Circus and Marble Arch this week.
The protests have led to road closures, traffic gridlock and serious disruption to public transport and local businesses, with 55 bus routes closed and 500,000 people affected.
The campaign group said it is planning to "non-violently disrupt Tube services to highlight the emergency of ecological collapse" today if the government does not meet its members.
It added: "Participants will peacefully break the law in order to stop the tube and then will wait to be arrested.
"We sincerely apologise to all those who may suffer as a consequence of this disruption. In any other circumstances we would never dream of disrupting the Tube but this is an emergency.
"We request that workers do not intervene in the protests to ensure that they go as smoothly and safely as possible for all involved."
It is not clear how the group plans to disrupt Tube services. But London Mayor Sadiq Khan said that while he shared the passion of the protesters about the urgent need to tackle climate change he was "extremely concerned" about plans to disrupt the London Underground.
In a statement posted on Twitter he said: "It is absolutely crucial to get more people using public transport, as well as walking and cycling, if we are to tackle this climate emergency - and millions of Londoners depend on the Underground network to get about their daily lives in our city.
"Targeting public transport in this way would only damage the cause of all of us who want to tackle climate change, as well as risking Londoners' safety and I'd implore anyone considering doing so to think again."
Groups of protesters remained in place through the night and into Wednesday morning at several locations, blocking the road at Marble Arch and Oxford Circus.
Four people ensconced in the road at Oxford Circus were playing cards and reported being visited by the police.
Meanwhile, a woman at Marble Arch, who gave her name as Virginia, said she had come from Oxford to join the protest "to keep the planet in good nick for my grandchildren".
Police earlier said 290 people had been arrested in connection with the demonstrations, with many of these at Waterloo Bridge.
Five people were arrested on suspicion of criminal damage following disruption outside commercial premises in Lambeth on Monday and have since been released under investigation.
The other 285 people were were arrested on Monday night and throughout Tuesday for Public Order Act offences, obstructing a highway and one for obstructing police as well as two further arrests for criminal damage at a commercial premises on Belvedere Road, Lambeth on Monday.
One arrested protester from Oxford called Ben said he was heading straight back to Marble Arch after being released from custody in the early hours of Wednesday morning.
"I was respectful, they were respectful and they had to let me go because they didn't have the resources to keep me in there, so I'm just keeping on rebelling basically," he said in a video published on the group's Twitter.
The Met imposed a 24-hour condition on Waterloo Bridge on Monday evening telling protesters to continue any demonstrations in the Marble Arch area, but on Tuesday said it extended it until Friday.
Another 24-hour condition was imposed in the Oxford Circus area on Tuesday and the Met said that a "number of arrests" had been made in the area that evening, but did not give details of how many or on what grounds.
It added: "There is a need to ensure the right balance is struck between allowing the right to peaceful protest, while disruption to communities is kept to a minimum." The Met warned that demonstrations are expected to continue "throughout the coming weeks".
A Transport for London spokesman said it was aware of plans for demonstrations on the Underground and urged people to check for travel updates before setting off.
"The safety of our customers and staff is our number one priority and we're already working closely with the police to manage the impact on London's transport network."
Elsewhere on Tuesday 29 people were arrested after hundreds of activists from the Extinction Rebellion Scotland group occupied Edinburgh's North Bridge, bringing traffic to a standstill.
This article was written by Press Association staff reporters.