English heritage is set to oppose all skyscrapers in historically sensitive areas, regardless of their design quality.
The warning will be included in a national consultation document to be published by EH and the Commission for Architecture and the Built Environment next Tuesday.

The document, called Guidance on Tall Buildings and written in response to the rash of skyscraper proposals around the country, will also call on planners to refer all proposals to both organisations.

The news will come as a blow to London mayor Ken Livingstone, who wants tall, iconic buildings clustered in the City of London and around the capital's parks.

It will also be seen as a retreat from the policy EH briefly followed under former chief executive Sir Jocelyn Stevens, when the organisation backed Lord Foster's "erotic gherkin" tower in the City of London. EH cited the tower's design as the deciding factor in lending its support.

The guidance is expected to say that EH will refuse skyscrapers planning permission if they damage or detract from conservation areas, historic parks, rivers or important views. Location will be EH's single most important consideration when assessing towers. Developers will not be able to circumvent the rule by appointing top architects.

The call for developers and local authorities to refer proposals to both organisations is set to be backed by the DETR, which is expected to write to planning authorities soon urging them to act accordingly.

This week, EH chief executive Sir Neil Cossons hit back strongly at Livingstone after the mayor claimed that the conservation body was undermining London's prosperity by blocking tower proposals.

In an exclusive interview with Building, Cossons described plans to build towers in the City of London as crass. He accused Livingstone of being too influenced by City businesses and planners. "Ken has a job to reconcile the unfettered interests of business with London as a city in which people can live and enjoy themselves," Cossons said.

He argued that the City skyline could be improved by demolishing some towers. He said: "If some of these buildings cease to be worth having we should make every effort to get them down."

EH and Livingstone's Greater London Authority are working together on a second document, to be published later this month, which will propose suitable sites for towers.

In the tall buildings guidance, CABE is expected to set out its arguments against so-called Trojan horse architecture, in which developers dilute the quality of their proposals once they have secured planning permission. CABE will seek guarantees of architectural quality before recommending approval.

Developers will also be expected to open substantial parts of tall buildings to the public.