Seeking to reflect his involvement in the anti-Vietnam War movement, he turned from painting to photomontage to better address his political views.
He is best known for the images he created for the Campaign for Nuclear Disarmament (CND) in the 1970s–80s including a détournement of John Constable's The Hay Wain called "Haywain with Cruise Missiles".
In it, Kennard writes about the possibilities of undertaking an aesthetic practice in relation to social change, and considers how his art has interacted with the politics of actual events.
They might be quoting Simone Weil who wrote: "There is a natural alliance between truth and affliction, because both of them are mute supplicants, eternally condemned to stand speechless in our presence."
[10]Kennard's 2003 photomontage Photo Op (in collaboration with Cat Phillips) of Tony Blair taking a selfie against a backdrop of burning oil, was described by The Guardian as "the definitive work of art about the war".
[12] It takes the form of a small book priced at £9.99, published by the Tate Gallery, which Kennard believed was a reasonably cheap and accessible way of getting his message to young people outside the artworld.
Created in 2013 in reaction to the 39th G8 summit in Enniskillen, Kennard has encouraged the public to "print, Tweet, Facebook, email and share these images as a sign of protest".
[21] In December 2019, along with 42 other leading cultural figures, Kennard signed a letter endorsing the Labour Party under Jeremy Corbyn's leadership in the 2019 general election.
The letter stated that "Labour's election manifesto under Jeremy Corbyn's leadership offers a transformative plan that prioritises the needs of people and the planet over private profit and the vested interests of a few.