The Shrewsbury North West Relief Road plans were reopened to public comments earlier this year after a raft of environmental documents were added.
Hundreds more objections have been filed, prompting Better Shrewsbury Transport (BeST) to once again urge Shropshire Council to shelve the project.
Councillor Richard Marshall, portfolio holder for highways with the council, suggested objectors were a "vocal minority" in a social media exchange. The authority believes the road will improve air quality in Shrewsbury town centre and bring economic benefits for the county town and beyond.
But BeST spokesman Mike Streetly responded: "We’ve seen senior councillors, who should know better, saying on social media that a record-breaking 5,000+ objections is just the response of a 'vocal minority'. It’s disappointing to see elected representatives dismiss detailed and evidence-based objections from their constituents in such an immature way.
"Is the administration really going to ignore concerns that this road isn’t fit for purpose? Democracy is supposed to be a dialogue."
The road, which would stretch for four miles from Churncote island to Battlefield and effectively complete a ring road around Shrewsbury, has raised major concerns over the environmental impact and cost implications. It was last priced up at around £81 million, but with soaring construction costs, the real figure will be significantly higher.
Mr Streetly added: "The huge number of objections is something never seen before in Shropshire’s planning history. It’s a sign of just how controversial this road is. Four local town councils, eight businesses, ten transport campaign groups, and eight environmental groups have all opposed it, along with thousands of residents.
"People in Shropshire feel they are being ignored, not least of all because the public consultation process was shut down early due to the pandemic. Council leader Lezley Picton has a choice. She can either engage with residents, or she can close her eyes, put her fingers in her ears, and pretend nothing is wrong."
Shropshire Council has been contacted for a comment.