Controversial proposals to build a 35-storey glass-fronted skyscraper yards from the Victorian heritage of Birmingham Council House and the Town Hall have split the city’s best known conservation groups.

In what is shaping up to be one of the bitterest planning rows for decades, the Victorian Society and the 20th Century Society have railed against the £160 million scheme for a 441ft-high office block on the corner of Colmore Row and Newhall Street, describing the design as an “incongruous leviathan” and an “abomination”.

On the other side of the fence lies Birmingham Civic Society, which has declared itself “90 per cent pleased” with the proposed British Land Tower, which may replace the NatWest Tower on the prominent site in the Colmore Row conservation area at the heart of the city’s central business district.

Civic Society spokesman Glyn Pitchford, who has been working closely with the council planning department in an attempt to reach an acceptable compromise over the scale and design of the new building, said: “We will not stand in the way of progress and we are not against tall buildings, but we need to make sure they add value to the street scene.

“I hate to use the word iconic, but this is the sort of quality building design that Birmingham lacks. It is certainly an awful lot better than what is on that site at the moment.”

But Mr Pitchford’s optimism is not shared by the council’s heritage and conservation panel, a body set up to advise the planning committee on sensitive development proposals.

Minutes of a recent meeting, published on the council website, record panel member Andy Foster, an architect, describing the British Land Tower as an “appalling scheme” which would destroy the conservation area.

Mr Foster went on to suggest planning mistakes of 50 years ago would be repeated if the “abominable project” were to be built.

He was joined by Eva Ling, of the 20th Century Society, who said Colmore Row was the city’s only remaining prestigious highway.

Views along Colmore Row to the Town Hall would be completely destroyed in the 35-storey structure was approved, Mrs Ling warned.

The Victorian Society, meanwhile, fears the new building would be even more dominant than the NatWest Tower, which since it was built in the early 1970s has often been described as one of Birmingham’s ugliest modern buildings.

In a letter to the conservation and heritage panel, the Victorian Society said: “The site is at the heart of the conservation area and the proposed building will dominate views within the conservation area itself, such as in Colmore Row, Chamberlain Square, Victoria Square, St Philip’s Cathedral and Newhall Street.

“It will also overshadow the Grade 1, 11* and 11 listed buildings of the area, including St Philip’s Cathedral and the Council House. The proposed building will not therefore preserve or enhance the character of the conservation area.”

The Victorian Society and 20th Century Society are pinning their hopes on the Government agreeing to list the NatWest Tower as a building of architectural importance, although English Heritage rejected an application last year.

Birmingham planning committee, which will have to decide later in the year whether to approve the British Land scheme, has already expressed unease at the scale of what is being proposed. Last month members said they were concerned the proposal amounted to over-development on a sensitive site and out of keeping with surrounding historic buildings.

The council’s political leadership, which regards the British Land Tower and the 2,500 jobs created by the scheme, as proof that Birmingham remains an attractive business location, is continuing to lobby in favour of the plan.

Council regeneration director Clive Dutton pleaded with planning committee members to consider the economic importance of developing Grade A offices on such a prominent site.