It is the latest blow to the apartment block project earmarked for the Oxford suburb of Jericho which, if approved, will see 54 flats and a public square built on a narrow strip of canal land adjacent a Grade II-listed church.
Although CABE's design panel has welcomed the height of the project and plans to open up views of St Barnabas Church from the canal, it fears the current designs will produce 'awkward' architecture.
In a statement the panel said: 'We have concerns regarding the apparent lack of thought given to the design of the public space and its relationship with the surrounding buildings.
'The manner in which this concept has been realised has led to an awkward geometry of the corners of both buildings and leaves an odd-shaped public space.
'A square of this size would benefit from more activity and a mix of uses. We are not convinced that single use is the right approach for this site and have reservations about the lack of animation of the central space,' the statement continued.
CABE has also questioned the connection between the private and public spaces and, in particular, has voiced doubts over whether the existing canalside walk will be maintained in front of the proposed residential blocks.
'Landscape design ideas for the central space must work alongside the architectural concepts for a robust and holistic response to this site and its assets,' added the panel.
CABE said it was 'generally supportive' of PRP's scheme but insisted it would 'substantially benefit' from further design work.
PRP declined to comment on CABE's comments. But a spokeswoman said: 'The Canalside project has yet to be approved for planning. A decision was meant to be made this month but has since been delayed and they are expecting the decision to be made next month.'
The delay follows vociferous local objection to the scheme. According to reports, Oxford City Council has received 500 complaints from angry local residents who fear the scheme will blight the environment.