Labour-controlled Corby Borough Council's Cube complex was built in November 2010 and is home to the town's theatre, library, register office and council offices.
Approximately 310 inmates are employed for bookbinding, carpentry, and locksmithing work as well as in jobs in the library, business office, kitchen and general housekeeping.
The campaigners object to the loss of disabled parking spaces as Wiltshire Council plan to create a "European-style piazza" at the centre of the city, claiming the eight spaces in the Guildhall Square are the only places within 250m of the Library, Post Office, and banks.