Chapman Taylor’s plans for Liverpool Waters would cause “serious harm” and compromise the city’s world heritage status, English Heritage has warned.

In a strongly worded letter to Liverpool City Council, the heritage watchdog criticised the scale of the development and called for a planning decision to be referred to government ministers.

English Heritage’s intervention marks the latest in a series of blows to developer Peel Holding’s scheme, which has been the subject of criticism by Design Council Cabe and Unesco in recent weeks.

Plans for a cluster of tall buildings at Clarence Dock are singled out for particular criticism by English Heritage, which warns that it will “overwhelm the historic, horizontal character of the docklands”.

The letter goes on to say that the density, mass and scale of the development “will compromise and unbalance the historic urban landscape of Liverpool as a whole”.

“We believe the impact of these proposals on the historic character of Liverpool as a whole…and on the significance and setting of many designated heritage assets is very serious,” wrote English Heritage’s North West planning director Henry Owen-John.

While Owen-John conceded that there are some positive benefits to the proposals, he concluded: “We believe that the harm is so serious and the value of the heritage so significant that national government should consider whether the matter should be called in for its own determination.”