City Hall filled with rubble ... in the name of art

Peter Kennard, renowned for his photomontage work, and Cat Picton Phillipps, who works with digital technology and cement, are mounting a major new exhibition in City Hall that will see the ground floor transformed into a unique mixed media installation called 'Demo'.

The artists, whose work 'Award' was recently bought by the Victoria and Albert Museum, will place hundreds of placards embedded in cement and rubble throughout the ground floor, alongside images covering the windows. The images, reflecting world events, will be visible inside and outside the building and use natural light to make passers by aware of their right to enter City Hall to view the free exhibition.

They said: "This installation represents a demo taking place in City Hall 24 hours a day, about war, poverty, ecology and the struggle of people across the world for human rights. We have worked to counter the geometric authority of City Hall, the seat of London Government, with placards, canvas and cement to make an organic human scale exhibition that everyone can relate to."

The exhibition has been produced to coincide with the European Social Forum in London.

The artists continued: "We wanted to create a powerful voice against government policy, which led to the war in Iraq. City Hall is an important public building available for the people of London. In recognition of the fact we want to make art that is not obscure and which communicates to the public on major issues of concern."

Mayor of London Ken Livingstone said: "It is important for City Hall to be a venue for exhibitions and art that communicates directly to the public on major issues of concern. The themes that 'Demo' covers are universal and I hope that Londoners as well as visitors to the capital will take the opportunity to see it."

• The installation will be in place between Monday 4 October and Friday 5 November. City Hall – on the southern riverbank, west of Tower Bridge – is open Monday-Friday 8am-8pm