Climate protesters have stormed the Royal Academy and glued themselves to a Leonardo Da Vinci painting.
Five Just Stop Oil supporters have spray-painted "No New Oil" in white letters onto the red slab under the vast painting in central London.
It is the fifth time the climate protesters have struck in a week at a major art gallery after allegedly targeting different art galleries in Manchester, Glasgow and London.
One of the protesters branded the Government as a "Judas" to future generations as he said the group had brought its campaign to this "magnificent beautiful painting" because the future is "bleaker than ever".
The painting represents a scene when Jesus announces that one of his 12 apostles will betray him, during the last time he dined with them before he was crucified.
The climate protesters are calling for the Government to halt new oil and gas licences in the UK and for the directors, employees and members of art institutions to join the Just Stop Oil protests.
During Tuesday's protest, one of the activists said: "The truth is any new oil expansion is a death sentence, a death sentence for the future.
"It is a death sentence for younger generations. It is a death sentence for the nature that has directly inspired art for hundreds of thousands of years."
He suggested the Government is "betraying the younger generations and those in the global south who are facing of the worst impacts" of climate change.
A Royal Academy spokesman said: "The room has been closed to the public. The police have been called upon the protestors' request."
Some of the protesters were named including Lucy Porter, 47 a former primary teacher from Leeds, Jessica Agar, a 21 year-old art student from Hereford, and Tristan Strange, 40, a community organiser from Swindon.
In a statement, Ms Porter said: "My job as a teacher was to encourage my students to take inspiration from the great works of art housed by institutions like the Royal Academy.
"How can our Government expect young people to respect culture when they are encouraging new oil and gas projects that will be our children's death sentence?"
Ms Agar added: "As an art student, I deeply respect and value the artworks themselves, but I also value the power that art has to change the world. It's that power I speak to today.
"Artists and galleries are failing to meaningfully take action against the climate emergency.
"No painting is worth more than my six-month old nephew's life. No sculpture can feed babies starving because extreme heat killed food crops."
Mr Strange added: "Time is running out to change course or prepare for disaster and the message is not reaching the public or our politicians. We must stop new oil and gas immediately.
"Da Vinci said that art is the Queen of all sciences communicating knowledge to all the generations of the world. The science still isn't being heard."
Leonardo da Vinci created The Last Supper between 1492 and 1497-48, and the RA's full-size copy of it was painted by one or more of his pupils.
The RA copy - which is attributed to Giampietrino and Giovanni Antonio Boltraffio - is believed to be the most accurate record of the original and was painted in around 1515-20.
The oil on canvas painting is about 3020mm x 7850mm, which makes it slightly smaller than the original.
In the last week, Just Stop Oil activists have allegedly attached themselves to a 19th-century landscape by Horatio McCulloch called My Heart's In The Highlands which hangs in Glasgow's Kelvingrove Art Gallery and Museum.
They are also alleged to have sprayed the group's logo on the walls and floor of the renowned gallery in orange paint.
In addition, they have also allegedly attached themselves to Vincent Van Gogh's 1889 work Peach Trees in Blossom at The Courtauld gallery in London.
Another alleged target has been a JMW Turner painting at Manchester Art Gallery.
Arrests were also made after two activists allegedly glued themselves onto the frame of John Constable's the Hay Wain at central London's National Gallery on Monday.
They covered it with a reimagined scene of the destruction that climate change could cause to the landscape.
A Metropolitan Police spokesman said: "At 11.37am on Tuesday July 5, police were called to Burlington House, Piccadilly following reports that protestors had glued themselves to artwork.
"Officers are in attendance. The incident is ongoing."
