I believe the world's leaders are not acting urgently enough to avert a climate catastrophe.
Londoners face a fourth day of disruption as environmental protesters vow to maintain roadblocks across the capital despite nearly 400 arrests.
Environment Secretary Michael Gove said "we've got the message" after some Extinction Rebellion (XR) activists glued themselves to a train and others chained themselves to Jeremy Corbyn's garden fence.
Scotland Yard said more than 100 people were arrested on Wednesday, bringing the total to almost 400 as ongoing protests continue in Parliament Square, Waterloo Bridge, Oxford Circus and Marble Arch.
On Wednesday night, campaigners were playing a cat-and-mouse game with police, who promised to continue the operation overnight.
Three people have been charged over an Extinction Rebellion protest where activists climbed on the top of a train at Canary Wharf station in east London, British Transport Police said.
Activists said they plan to continue roadblocks, which have affected more than half a million people with traffic gridlock and disruption to transport and businesses since Monday, until at least next Friday.
Robin Boardman-Pattison, 21, who walked off during an interview with Sky News, said activists were planning to step up action on the rail and London Underground network.
"We will be escalating our disruption throughout the week," he said. "The impact to the Tube system will grow."
Asked about the protests on the BBC's The One Show, Mr Gove said: "I think it's appropriate for people to make their feelings known but I also think, we've got the message, we understand that action needs to be taken."
London Mayor Sadiq Khan said on Twitter: "We're facing a climate emergency. I fully support the right of protesters to protest on this vital issue, and urge organisers to work with police to ensure their demonstrations are peaceful and lawful and that disruption is kept to a minimum."
XR, which is demanding a meeting with the government, has said direct action is needed to force authorities to act urgently on climate change and wildlife declines and halt a "sixth mass extinction".
TV presenter and naturalist Chris Packham joined protesters at Oxford Circus on Wednesday, saying: "I believe the world's leaders are not acting urgently enough to avert a climate catastrophe. As long as it is peaceful and democratic then they can count on my support."
Some Londoners were critical of the group's methods, which are causing disruption to their lives. A YouGov poll suggested public opinion has swung against the protests.
The survey of 3,561 British adults showed 52% either "somewhat oppose" or "strongly oppose" the action, compared with 36% who "strongly support" or "somewhat support" it.
This article is based on copy supplied by the Press Association.