Police have the government’s “full support” in a crackdown on environmental protesters who have caused days of travel disruption in London, the home secretary has said.
“I totally condemn any protesters who are stepping outside the boundaries of the law,” he added.
“They have no right to cause misery for the millions of people who are trying to lead their daily lives. Unlawful behaviour will not be tolerated.
“I expect the police to take a firm stance and use the full force of the law. They have my full backing in doing so.
“I have spoken to the Met Commissioner today to offer her whatever support she may need and pass on my appreciation to the thousands of officers patrolling the streets of the capital over the bank holiday.
“We are a proud democracy – and no one should be allowed to break the law without consequence.”
More than 460 demonstrators have so far been arrested, mostly for obstruction highways and violating conditions imposed under the Public Order Act in an attempt to move them to the legal protest site at Marble Arch.
Mr Javid said Extinction Rebellion had disrupted commuters, businesses, emergency vehicles and “put added pressure on police officers whose job it is to solve crimes and protect the public”.
Cressida Dick, commissioner of the Metropolitan Police, said more than 1,000 officers were being deployed every day to police the protests in London.
A spokesperson for Scotland Yard said the protests were "putting strain" on the force, making it put officers on 12-hour shifts and cancel rest days.
"The protesters need to understand that their demonstration is meaning officers are being diverted away from their core local duties that help keep London safe and that this will have implications in the weeks and months beyond this protest as officers take back leave and the cost of overtime," a statement added.
The Violent Crime Taskforce has had its Easter leave cancelled in order to "retain the capacity to deal with any unrelated violent incidents".
Police had previously been given extra funding for Brexit preparations and to fight rising knife crime.
The mayor of London, Sadiq Khan, had written to the home secretary warning of “increasing cost to the Metropolitan Police” from Extinction Rebellion and Brexit protests.
“The Met’s ability to police protests without impacting on core policing priorities – such as tackling knife crime – has been made significantly harder by the huge cuts to government police funding,” he added.
Mr Khan said the right to protest must be “balanced against the need to ensure the safety and security of all Londoners, as well as the continued running of our city”.
Mr Javid said he would “discuss any support the force needs in the coming days”, for example if it needs to request officers from other areas to boost ranks.
Amid anger from commuters and businesses, Scotland Yard said there was "no legal basis" to contain peaceful protesters.
The force said most of those arrested were being "released under investigation" to be interviewed at a later date, and may re-join demonstrations.
While some police officers have been accused of heavy-handed tactics while physically carrying protesters into vans, others were filmed dancing with demonstrators in Oxford Circus.
Metropolitan Police Commander Jane Connors said she was “disappointed” by the footage and called the dancing “unacceptable behaviour”.
“We expect our officers to engage with protesters but clearly their actions fall short of the tone of the policing operation at a time when people are frustrated at the actions of the protesters,” she added.
"We will be reminding officers of their responsibilities and expectations in policing this operation.”
Extinction Rebellion organisers say they are prepared to escalate the group's tactics - possibly by targeting Heathrow Airport - if their demands “are not met” and expect thousands more protesters to join them over the Easter bank holiday weekend.
Co-founder Dr Gail Bradbrook said the first criminal charges against demonstrators would not discourage supporters.
“There are ten times that number [arrested] prepared to be arrested,” she added. "The hollowed-out British state is overwhelmed."
A protester in Oxford Circus told The Independent she had received both insults and gratitude from members of the public.
The woman, who gave her name as Sian from Wales, said: "Our ultimate aim is for the government to take notice and act - the disruption isn't about causing problems for individual people."
Campaigners issued a direct challenge to the environment secretary, Michael Gove, saying: “We are happy to discuss leaving if you are happy to discuss the climate crisis with us and how we find solutions that focus on principles of fairness and justice.”
Three protesters appeared at Highbury Corner Magistrates' Court after allegedly obstructing DLR trains at Canary Wharf station on Wednesday morning.
Cathy Eastburn, 51, Mark Ovland, 35, and Luke Watson, 29, pleaded not guilty and were remanded in custody.
Some protesters have chained themselves to Jeremy Corbyn's garden fence, parts of Oxford Street remain closed for a street party-style protest and around 100 tents are pitched at Marble Arch.
Waterloo Bridge has been lined with banners, trees and tents, amid music, workshops and talks, and protesters have periodically been trying to set up camp in Parliament Square before being moved on by police.
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