The Canterbury Society will hold a pilgrimage through city streets to highlight the issue of clean air.
It is also in part a protest against the city council’s decision to press ahead with a 370-space multi-storey car park in Station Road West.
Beginning at St Dunstan’s Church, the pilgrimage will retrace some of the steps taken by Henry II following the murder of Archbishop of Canterbury Thomas Becket nearly 850 years ago.
Organiser Victoria Field says: “We are asking people to come and march, joyfully but purposefully to protest against the multi-storey and to celebrate what we value about our city.
“Bring banners, wear historic costumes, play musical instruments and show your commitment to creating a cleaner, kinder, contemporary Canterbury.”
Critics of the multi-storey believe that it will encourage traffic to the area and thereby worsen air pollution.
They also argue that the council does not do enough to monitor harmful pollutants entering the city’s atmosphere.
Professor Jan Pahl, chairman of the Canterbury Society, added: “If you care about the air that children breathe or if you care about reducing traffic on our roads come on this pilgrimage.”
The Pilgrimage for Clean Air starts from St Dunstan’s Church at 10.30am on Saturday, 29 December. It will last roughly 90 minutes and there will be marshals along the route.