Chapman Taylor’s £5.5 billion Liverpool Waters scheme has taken a second hammering from Design Council Cabe.

Its latest design review said the revised masterplan for the 1.3 million sq m project, which was submitted for outline planning last year, was “weakly expressed”.

It also criticised the design principles as too vague to guarantee the quality of what will be built over the next 30 years.

The development, with its 55-storey landmark Shanghai Tower, has alarmed conservationists, and Unesco has threatened to strip Liverpool of its World Heritage Site status if construction goes ahead.

The plans were revised after Cabe gave the scheme a critical design review a year ago, but this has done little to allay concerns.

Cabe’s latest review acknowledged the “potential” of Peel Holdings’ plan but said it was “hindered by a weakly expressed masterplan” and principles that were not strong enough to help planners resist inappropriate future applications.

The reviewers said: “We do not yet have the confidence that the parameters will provide a sound basis by which to control design quality across the Liverpool Waters site. We ask that the design team revise them.”

It warned the failure to set maximum heights and footprints for buildings could cause uncertainty and confusion. And it raised “serious questions” over the scheme’s connectedness to its surroundings.

The review also criticised the architects for failing to include a sufficiently detailed and fully illustrative spatial masterplan for the whole site, thus failing to articulate the vision.

Chapman Taylor declined to comment.