Organisations against the pedestrianisation of Exeter's Paris Street look set to join forces to oppose the move.
The street is due to close to traffic as part of the new shopping and leisure development on the bus station site.
But critics believe it will lead to congestion in surrounding streets and affect bus services.
Keith Lewis, chairman of the Exeter civic society, says he will be working with Transition Exeter, the Green party and National Express to oppose the move.