"We just want to be left alone, to make our own judgments," says Joe Anderson, the forthright, newly minted, directly elected mayor of Liverpool and before that leader of the city's council. He is talking about Liverpool Waters, a development at the scale of Canary Wharf and designed like Dubai, covering 60 hectares with clusters of skyscrapers and 1.7 million sq metres of offices, homes and shopping. It will create, says Anderson, 17,000 jobs and bring in £5.5bn of investment.

His only problem is that the proposed development partly straddles a world heritage site, and includes within its boundary some of the mightiest docks and warehouses of the Industrial Revolution. Just outside are the Three Graces, the majestic Edwardian commercial buildings that, along with its two cathedrals, define the image of the city. Being a world heritage site means that new development has to respect and enhance what is called its "outstanding universal value", something which Unesco says the development signally fails to do. English Heritage and Cabe (Commission for Architecture and the Built Environment ) have persistently objected to aspects of the scheme, despite which Liverpool city council granted it outline planning permission in March. The question now is whether Eric Pickles, as secretary of state for communities and local government, decides to hold a public inquiry.

According to Unesco, the outstanding universal value of the site "would be irreversibly damaged if the development goes ahead". English Heritage says that "the setting of some of Liverpool's most significant historic buildings will be severely compromised, the archaeological remains of parts of the historic docks are at risk of destruction, and the city's historic urban landscape will be permanently unbalanced". It also says that the information provided by the developer, the Peel Group, and the architectural practice, Chapman Taylor, is not sufficient for an application of this importance, and that their assessments are inadequate.

Cabe says that the scheme neither "articulates a vision for Liverpool Waters" nor demonstrates how its elements "have been integrated into a coherent whole". The developer's "design principles" are not "organised or expressed in a meaningful way" and do not give confidence that they "will provide a sound basis by which to control design quality". It says that the official guidance for proposing tall buildings has not been followed. It's unusual to find so much unanimity among the various bodies charged with expressing views on major projects. What they are saying, in their measured consultee-speak, is that it stinks.

Looking at the proposals you can see their point. The development's towers would loom large behind the Three Graces and, large though they are, the old warehouses would become bits of flotsam in a sea of what, until it is proved otherwise, looks like very average commercial development. There is no sign whatsoever of an attempt to make a relationship between the new buildings and the old. Instead, from its first proposals five years ago, Peel has kept proposing essentially the same thing: a wannabe Dubai, or a Shanghai-lite, plonked carelessly next to the historic buildings. Anderson talks of reviving the pride of the city's forefathers, but there is little pride in these knock-offs of other cities.

Liverpool city council and Peel jointly agreed that their aim was an "aspirational scheme" which will "create a new sense of place", but there is nothing in the images to suggest anything other than generic blandness. Also, that it would "integrate" the site's heritage with "exciting and sustainable new development". It doesn't. And that it would "draw on the unique identity of the site and the city to… reinforce Liverpool's strong identity". Again there is absolutely no sign of this. These words are products of a busy day at the flannel factory.

It's not just that the designs are not very good, but also that Peel has declined requests by Cabe and English Heritage to demonstrate fully how it would achieve the sort of architectural quality and sensitivity to the past which everyone in theory agrees is a good thing. (Nor, for that matter, would it answer a simple request for information for this article.)

The planning permission it has is for an outline scheme, with detailed design to be decided later. It permits a lot of big buildings without showing the architectural genius by which it would make them beautiful. The burden of proof is with Peel to show that dense clusterings of very large buildings would not trash the surroundings, but that proof has not been supplied. Possibly because it's impossible to prove this point – that there is such a thing as too big and too tall on this site which no amount of design can massage away.

There are, of course, all those jobs, and it would be a rash and heartless politician who would snatch away thousands of potential livelihoods from Liverpudlians for the sake of what Anderson has called "a certificate on the wall in the town hall", by which he means the world heritage site status. Except that this is to make the large assumptions that Peel will find £5.5bn of capital that it doesn't currently have, and that Liverpool will suddenly discover enough office demand to fill this massive development.

A more likely outcome is that the favourable planning permission will allow the Peel Group to write up the value of the site on its balance sheets. It will have also established principles, if they can be called that, that will allow Peel to do almost whatever it wants with the site in the future. Liverpool would lose twice – the city wouldn't get all the promised jobs, and its heritage would be compromised.

It is in fact possible to have both development and respect for the past. Anderson says that this is his aim, and that Liverpool Waters achieves it. That Unesco, Cabe and English Heritage, plus several other bodies, disagree with him is, he says, "a matter of opinion", which ignores the fact that theirs are considered expert opinions that are in theory given weight by the planning process. It is not that they should always have the last word, but when there is such a chorus of disapproval on such a significant site, it demands to be addressed more seriously than has so far happened.

Anderson also urges me to look at Peel's original proposals to see how many concessions it has made. I do, and I see that they were even more overbearing than the present ones, but not fundamentally different. I see one of the oldest ploys in developers' books: start with something more than outrageous, with the aim of achieving the merely outrageous. Liverpool should be smart enough not to fall for that one.

Pickles will be lobbied to the effect that he should encourage business and localism and leave Liverpool Waters alone, but if ever a project demanded a public inquiry it is this. It is a site of national and international importance – as the world heritage site designation recognises – where serious and legitimate concerns have been raised, and have not been adequately dealt with by the local authority. According to the World Heritage Convention, signed by Britain, the government "has a duty to protect, conserve, present and transmit the property to future generations". Waving Peel's project through would not fulfil this duty.