More than 1,100 Extinction Rebellion activists have been arrested since Monday as it was revealed a British billionaire is a major financial backer of the environmental group.

The fourth day of demonstrations focused on London City Airport, where protesters attempted a “Hong Kong-style occupation of the terminal building” with hundreds blocking the main entrance.

The update on arrests comes as it was revealed Sir Christopher Hohn, who is worth £1.2 billion, made a personal donation of £50,000 to the environmental group, according to the Daily Telegraph.

“I recently gave them £50,000 because humanity is aggressively destroying the world with climate change and there is an urgent need for us all to wake up to this fact,” Mr Hohn told the newspaper.

The Children’s Investment Fund Foundation, a charity co-founded by the billionaire, has also donated more than £150,000.

Activists also blocked the entrance road, climbed on to the terminal roof and glued themselves to the entrance of the Docklands Light Railway (DLR) station serving the east London airport on Thursday.

Extinction Rebellion claims planned expansion of the airport is incompatible with meeting the Government’s legally binding commitment to cut emissions to net-zero by 2050.

An Aer Lingus flight from City Airport to Dublin was delayed when a protester on board stood up to deliver a lecture on climate change just as the plane was due to take off.

Extinction Rebellion protests
Footage of a protester on top of a plane was broadcast on Facebook by the protest group (Extinction Rebellion/PA)

And one man, identified by Extinction Rebellion as former Paralympic cyclist James Brown, who is visually impaired, managed to get on top of a British Airways plane at the airport.

His actions were branded “reckless, stupid and dangerous” by Met Commissioner Dame Cressida Dick.

She said: “My early understanding is somebody has been arrested after they… presumably bought a ticket, went through security perfectly normally, went up the steps of a plane and hurled themselves on top of a plane.

“Actually, that was a reckless, stupid and dangerous thing to do for all concerned. But I think you can see that is quite a hard thing to predict or stop from happening.”

Police said more than 1,100 people have been arrested this week since protests began around Parliament and Whitehall on Monday, including around 50 at the airport on Thursday.

A tweet by the force said there had been some 1,112 arrests as of 8pm on Thursday.

Dame Cressida insisted Scotland Yard has enough cells to hold and process all of the activists, but she said officers were being taken away from tackling knife crime or safeguarding children to police the demonstrations.

She said the protesters were “utterly irresponsible and completely unreasonable” for their determination to take over and occupy important arterial roads in London for a two-week period.

She urged them to demonstrate in the pedestrian area of Trafalgar Square, saying: “Protest lawfully or go home.”

Extinction Rebellion protests
Protesters blocked the road outside City Airport, London (Kirsty O’Connor/PA)

But in a statement, Extinction Rebellion raised concerns that extreme weather caused by climate change would lead to crop losses, food crises, social unrest and damage to infrastructure, and people were risking arrest to show “how vulnerable we are”.

The protests in the capital are part of an “international rebellion” happening in cities around the world, calling for urgent action to tackle climate change and wildlife losses.

Those arrested at the airport include 83-year-old Phil Kingston, who has now been detained three times as part of Extinction Rebellion protests in the past week.

Extinction Rebellion co-founder Gail Bradbrook spoke outside the airport terminal on Thursday afternoon as the number of protesters that remained at the site dwindled.

Speaking to the PA news agency about the success of the demonstration, she said: “I think the most important thing is that we are alerting the British people to the crisis that we’re in and the threat to all the forms of business-as-usual.”

Shortly after 7pm, Robert Sinclair, chief executive of London City Airport, said there were no longer any protesters outside the terminal.

“We continue to work with the Metropolitan Police to ensure that our passengers tonight and tomorrow have a safe and secure service,” he said.

“The airport has remained fully operational throughout the day and has run an almost complete schedule of flights, with just two flights cancelled as a result of the protest activity.”

In central London, roads around Parliament and Whitehall remained closed to traffic apart from cyclists amid a heavy police presence, with protesters camped in Trafalgar Square and nearby St James’s Park, where police were working to clear the camp.