Designers said the project would improve safety, encouraging more people to take up cycling and walking and help hit net zero carbon emission targets, according to the Local Democracy Reporting Service.
Opponents said the scheme did not go far enough and would create narrow bottlenecks for lorries with the unintended consequence of even more traffic.
According to Mr Spencer, the decision “failed to consider” wider ramifications including the potential loss of £6m of funding from Active Travel England.
He said assessments found stretches along the London Road scheme to be short of safety standards for cyclists and pedestrians and that no alternative ideas had been put forward.
Mr Spencer claimed comments by cabinet members made clear the rejection “was solely on the grounds that the scheme would not be sufficiently safe for disabled pedestrians” but claimed “no evidence in support of that view was presented at the meeting other than hearsay”.