Two climate protesters caused more than £1,000-worth of damage to a “national treasure” painting after taping posters on top of and gluing themselves to The Hay Wain, a court heard on Tuesday.

Hannah Hunt, 23, and Eben Lazarus, 22, taped printed posters of a “dystopian version” of the artwork on to John Constable’s painting before gluing their hands to its frame in The National Gallery on July 4 this year, Westminster Magistrates’ Court was told.

The Hay Wain, which was painted in 1821, shows a rural Suffolk scene of a wagon returning to the fields across a shallow ford for another load.

Prosecutor Jonathan Bryan described the painting as “an important work of art” that could be described as “a national treasure”.

He added: “Important works of art which form part of a nation’s heritage need to be protected.”

Hunt and Lazarus, both of High Street, Trowbridge, are charged with causing criminal damage and the court heard there was “no issue” that what they did caused damage.

Their actions were said to be associated with climate change campaign group Just Stop Oil (JSO).

The pair will argue that Articles 10 and 11 under the European Convention of Human Rights – the rights to freedom of expression and freedom of assembly respectively – give them lawful excuse for their actions, the court heard.

Mr Bryan said the defendants entered the gallery accompanied by three others.

They are alleged to have waited for the others to distract security officers before taking out three printed posters of a “dystopian version of Constable’s painting” and taping them on to the canvas.

Hunt and Lazarus then glued their hands to the painting’s frame before delivering a short speech to people in the gallery, the court heard.

Police arrived and arrested them after security ushered members of the public out of the gallery.

The painting was taken to be be restored at the cost of £1,081 and fitted with a glass sheet before it was re-exhibited the next morning, according to the head of conservation at the gallery.

CCTV of the incident was played in court in which Hunt and Lazarus can be seen gluing themselves to the painting’s frame wearing JSO T-shirts.

In the footage, Lazarus said: “Art is important. It should be held for future generations to see, but when there is no food what use is art?

“When there is no water, what use is art? When billions of people are in pain and suffering, what use then is art?”

He added that he had stuck a reimagined version of The Hay Wain which showed the “destructive nature of our addiction to oil”.

The protester went on: “It is not more important than the 3.5 billion people already in danger because of the climate crisis. It is not more important than the lives of my siblings and every generation that we are condemning to an unlivable future.”

Hunt was then filmed adding: “New oil is a death project by our Government.

“My hand is glued to this painting but there is blood on the hands of our Government.”

Hunt and Lazarus deny criminal damage.

The trial continues.