Above photo: Prisoners for Palestine via AFP.
Thunberg joined the London demonstration to spotlight Palestine Action supporters on a near-fatal hunger strike.
Climate activist Greta Thunberg was arrested in central London on 23 December during a demonstration supporting imprisoned Palestine Action members, who doctors warn are at “imminent risk of death,” due to a weeks-long hunger strike.
City of London Police detained the 22-year-old under Section 13 of the Terrorism Act 2000 for displaying a placard backing the proscribed organization.
Video footage captured by Prisoners for Palestine shows Thunberg holding a sign. It read: “I support the Palestine Action prisoners. I oppose genocide.”
BREAKING: Greta Thunberg arrested under the Terrorism Act for holding a sign which says "I support Palestine Action prisoners. I oppose genocide"
She was detained at the Prisoners for Palestine action at Aspen Insurance in London, insurers for Israeli weapons firm Elbit Systems. pic.twitter.com/3qBt3iRi9e
— Prisoners For Palestine (@Prisoners4Pal) December 23, 2025
The protest unfolded outside Aspen Insurance’s central London offices, which demonstrators specifically targeted for its services to Elbit Systems.
Elbit is Israel’s leading arms company and has openly promoted its weapons as “battle-tested” across Israel’s many theaters of war over the past two years, including during the genocide in Gaza.
During the demonstration, two activists sprayed red paint onto the building’s facade, prompting police to move in and make arrests.
Greta Thunberg could have become a state-approved civil society “climate activist” — instead she has put herself on the line again and again to oppose genocide and Western complicity.
She is a light in the darkness. pic.twitter.com/YcJbW9fcZR
— Philip Proudfoot (@PhilipProudfoot) December 23, 2025
Thunberg was present at the protests to draw attention to eight anti-genocide activists who have been held on remand and began a hunger strike on 2 November, with at least five hospitalized after weeks without food, including cases of collapse, loss of mobility, and critical deterioration.
At least three strikers have stopped refusing food as their physical condition became critical or near fatal, while others continue in their hunger strike.
Lawyers representing the imprisoned Palestine Action activists have warned the UK government that they will seek a High Court case after the justice secretary refused to meet them.
Palestine Action became a banned organization in July under the 2000 Terrorism Act following an incident at Royal Air Force Brize Norton base where activists vandalized two aircraft.
Since the ban, over 2,400 pro-Palestine protesters have been arrested throughout the UK in connection with Palestine Action, now joined by Thunberg.
In September, a mass arrest took place in London where approximately 890 people were arrested at a rally against the ban, with 857 of those specifically for “supporting a proscribed organization”.