A public inquiry is taking place into controversial plans for a 472ft (144m) tower block on London's South Bank.
Critics say the tower would have a negative impact on the South Bank
English Heritage has attacked the proposal, saying it would harm some of the capital's best-loved views.
The 43-storey Doon Street building would ruin two famous views and affect the view of historic buildings and conservation areas nearby, it claimed.
Developers Coin Street said the tower would provide much-needed housing and community facilities.
The inquiry at Lambeth town hall will hear that Coin Street wants to develop up to 329 new homes and use income from the flats to subsidise public facilities including a new swimming pool.
English Heritage described the tower as "a large, angular mass towering over the delicate skyline of spires and domes which currently define the buildings within the view".
Philip Davies of English Heritage, said: "Londoners - and the millions of people who visit our capital each year - deserve better."
He added the development would "seriously harm" the world-famous view of Whitehall from the bridge in St James's Park and the "sublime symmetry" of the courtyard of Somerset House.
Iain Tuckett, Coin Street's group director, said the proposals would provide much-needed community facilities.
The plans had the support of the National Theatre, the Southbank Centre, the Tate Gallery, local MP Kate Hoey, the South Bank Employers' Group, Lambeth Council and the Mayor of London, he added.